diff --git a/app/api/controller/pullreq/codeowner.go b/app/api/controller/pullreq/codeowner.go
index c1bf433dc..0cdbd0044 100644
--- a/app/api/controller/pullreq/codeowner.go
+++ b/app/api/controller/pullreq/codeowner.go
@@ -67,17 +67,34 @@ func mapCodeOwnerEvaluation(ownerEvaluation *codeowners.Evaluation) []types.Code
 	codeOwnerEvaluationEntries := make([]types.CodeOwnerEvaluationEntry, len(ownerEvaluation.EvaluationEntries))
 	for i, entry := range ownerEvaluation.EvaluationEntries {
 		ownerEvaluations := make([]types.OwnerEvaluation, len(entry.OwnerEvaluations))
+		userGroupOwnerEvaluations := make([]types.UserGroupOwnerEvaluation, len(entry.UserGroupOwnerEvaluations))
 		for j, owner := range entry.OwnerEvaluations {
-			ownerEvaluations[j] = types.OwnerEvaluation{
-				Owner:          owner.Owner,
-				ReviewDecision: owner.ReviewDecision,
-				ReviewSHA:      owner.ReviewSHA,
+			ownerEvaluations[j] = mapOwner(owner)
+		}
+		for j, userGroupOwnerEvaluation := range entry.UserGroupOwnerEvaluations {
+			userGroupEvaluations := make([]types.OwnerEvaluation, len(userGroupOwnerEvaluation.Evaluations))
+			for k, userGroupOwner := range userGroupOwnerEvaluation.Evaluations {
+				userGroupEvaluations[k] = mapOwner(userGroupOwner)
+			}
+			userGroupOwnerEvaluations[j] = types.UserGroupOwnerEvaluation{
+				ID:          userGroupOwnerEvaluation.ID,
+				Name:        userGroupOwnerEvaluation.Name,
+				Evaluations: userGroupEvaluations,
 			}
 		}
 		codeOwnerEvaluationEntries[i] = types.CodeOwnerEvaluationEntry{
-			Pattern:          entry.Pattern,
-			OwnerEvaluations: ownerEvaluations,
+			Pattern:                   entry.Pattern,
+			OwnerEvaluations:          ownerEvaluations,
+			UserGroupOwnerEvaluations: userGroupOwnerEvaluations,
 		}
 	}
 	return codeOwnerEvaluationEntries
 }
+
+func mapOwner(owner codeowners.OwnerEvaluation) types.OwnerEvaluation {
+	return types.OwnerEvaluation{
+		Owner:          owner.Owner,
+		ReviewDecision: owner.ReviewDecision,
+		ReviewSHA:      owner.ReviewSHA,
+	}
+}
diff --git a/app/services/codeowners/service.go b/app/services/codeowners/service.go
index be0128b40..e18685486 100644
--- a/app/services/codeowners/service.go
+++ b/app/services/codeowners/service.go
@@ -21,6 +21,7 @@ import (
 	"io"
 	"strings"
 
+	"github.com/harness/gitness/app/services/usergroup"
 	"github.com/harness/gitness/app/store"
 	"github.com/harness/gitness/errors"
 	"github.com/harness/gitness/git"
@@ -37,6 +38,8 @@ const (
 	// maxGetContentFileSize specifies the maximum number of bytes a file content response contains.
 	// If a file is any larger, the content is truncated.
 	maxGetContentFileSize = oneMegabyte * 4 // 4 MB
+	// userGroupPrefixMarker is a prefix which will be used to identify if a given codeowner is usergroup.
+	userGroupPrefixMarker = "@"
 )
 
 var (
@@ -71,10 +74,11 @@ type Config struct {
 }
 
 type Service struct {
-	repoStore      store.RepoStore
-	git            git.Interface
-	principalStore store.PrincipalStore
-	config         Config
+	repoStore         store.RepoStore
+	git               git.Interface
+	principalStore    store.PrincipalStore
+	config            Config
+	userGroupResolver usergroup.Resolver
 }
 
 type File struct {
@@ -99,8 +103,15 @@ type Evaluation struct {
 }
 
 type EvaluationEntry struct {
-	Pattern          string
-	OwnerEvaluations []OwnerEvaluation
+	Pattern                   string
+	OwnerEvaluations          []OwnerEvaluation
+	UserGroupOwnerEvaluations []UserGroupOwnerEvaluation
+}
+
+type UserGroupOwnerEvaluation struct {
+	ID          string
+	Name        string
+	Evaluations []OwnerEvaluation
 }
 
 type OwnerEvaluation struct {
@@ -114,12 +125,14 @@ func New(
 	git git.Interface,
 	config Config,
 	principalStore store.PrincipalStore,
+	userGroupResolver usergroup.Resolver,
 ) *Service {
 	service := &Service{
-		repoStore:      repoStore,
-		git:            git,
-		config:         config,
-		principalStore: principalStore,
+		repoStore:         repoStore,
+		git:               git,
+		config:            config,
+		principalStore:    principalStore,
+		userGroupResolver: userGroupResolver,
 	}
 	return service
 }
@@ -284,11 +297,12 @@ func (s *Service) getApplicableCodeOwnersForPR(
 	}, err
 }
 
+//nolint:gocognit
 func (s *Service) Evaluate(
 	ctx context.Context,
 	repo *types.Repository,
 	pr *types.PullReq,
-	reviewer []*types.PullReqReviewer,
+	reviewers []*types.PullReqReviewer,
 ) (*Evaluation, error) {
 	owners, err := s.getApplicableCodeOwnersForPR(ctx, repo, pr)
 	if err != nil {
@@ -299,36 +313,41 @@ func (s *Service) Evaluate(
 		return &Evaluation{}, nil
 	}
 
-	flattenedReviewers := flattenReviewers(reviewer)
 	evaluationEntries := make([]EvaluationEntry, len(owners.Entries))
 
 	for i, entry := range owners.Entries {
 		ownerEvaluations := make([]OwnerEvaluation, 0, len(owners.Entries))
+		userGroupOwnerEvaluations := make([]UserGroupOwnerEvaluation, 0, len(owners.Entries))
 		for _, owner := range entry.Owners {
-			if pullreqReviewer, ok := flattenedReviewers[owner]; ok {
-				ownerEvaluations = append(ownerEvaluations, OwnerEvaluation{
-					Owner:          pullreqReviewer.Reviewer,
-					ReviewDecision: pullreqReviewer.ReviewDecision,
-					ReviewSHA:      pullreqReviewer.SHA,
-				})
+			// check for usrgrp
+			if strings.HasPrefix(owner, userGroupPrefixMarker) {
+				userGroupCodeOwner, err := s.resolveUserGroupCodeOwner(ctx, owner[1:], reviewers)
+				if errors.Is(err, usergroup.ErrNotFound) {
+					log.Ctx(ctx).Debug().Msgf("usergroup %q not found hence skipping for code owner", owner)
+					continue
+				}
+				if err != nil {
+					return nil, fmt.Errorf("error resolving usergroup :%w", err)
+				}
+				userGroupOwnerEvaluations = append(userGroupOwnerEvaluations, *userGroupCodeOwner)
 				continue
 			}
-			principal, err := s.principalStore.FindByEmail(ctx, owner)
+			// user email based codeowner
+			userCodeOwner, err := s.resolveUserCodeOwnerByEmail(ctx, owner, reviewers)
 			if errors.Is(err, gitness_store.ErrResourceNotFound) {
-				log.Ctx(ctx).Info().Msgf("user %s not found in database hence skipping for code owner: %v",
-					owner, err)
+				log.Ctx(ctx).Debug().Msgf("user %q not found in database hence skipping for code owner", owner)
 				continue
 			}
 			if err != nil {
-				return &Evaluation{}, fmt.Errorf("error finding user by email: %w", err)
+				return nil, fmt.Errorf("error resolving user by email : %w", err)
 			}
-			ownerEvaluations = append(ownerEvaluations, OwnerEvaluation{
-				Owner: *principal.ToPrincipalInfo(),
-			})
+			ownerEvaluations = append(ownerEvaluations, *userCodeOwner)
 		}
+
 		evaluationEntries[i] = EvaluationEntry{
-			Pattern:          entry.Pattern,
-			OwnerEvaluations: ownerEvaluations,
+			Pattern:                   entry.Pattern,
+			OwnerEvaluations:          ownerEvaluations,
+			UserGroupOwnerEvaluations: userGroupOwnerEvaluations,
 		}
 	}
 
@@ -338,6 +357,62 @@ func (s *Service) Evaluate(
 	}, nil
 }
 
+func (s *Service) resolveUserGroupCodeOwner(
+	ctx context.Context,
+	owner string,
+	reviewers []*types.PullReqReviewer,
+) (*UserGroupOwnerEvaluation, error) {
+	usrgrp, err := s.userGroupResolver.Resolve(ctx, owner)
+	if err != nil {
+		return nil, fmt.Errorf("not able to resolve usergroup : %w", err)
+	}
+	userGroupEvaluation := &UserGroupOwnerEvaluation{
+		ID:   usrgrp.ID,
+		Name: usrgrp.Name,
+	}
+	ownersEvaluations := make([]OwnerEvaluation, 0, len(usrgrp.Users))
+	for _, uid := range usrgrp.Users {
+		pullreqReviewer := findReviewerInList("", uid, reviewers)
+		// we don't append all the user of the user group in the owner evaluations and
+		// append it only if it is reviewed by a user.
+		if pullreqReviewer != nil {
+			ownersEvaluations = append(ownersEvaluations,
+				OwnerEvaluation{
+					Owner:          pullreqReviewer.Reviewer,
+					ReviewDecision: pullreqReviewer.ReviewDecision,
+					ReviewSHA:      pullreqReviewer.SHA,
+				},
+			)
+			continue
+		}
+	}
+	userGroupEvaluation.Evaluations = ownersEvaluations
+
+	return userGroupEvaluation, nil
+}
+
+func (s *Service) resolveUserCodeOwnerByEmail(
+	ctx context.Context,
+	owner string,
+	reviewers []*types.PullReqReviewer,
+) (*OwnerEvaluation, error) {
+	pullreqReviewer := findReviewerInList(owner, "", reviewers)
+	if pullreqReviewer != nil {
+		return &OwnerEvaluation{
+			Owner:          pullreqReviewer.Reviewer,
+			ReviewDecision: pullreqReviewer.ReviewDecision,
+			ReviewSHA:      pullreqReviewer.SHA,
+		}, nil
+	}
+	principal, err := s.principalStore.FindByEmail(ctx, owner)
+	if err != nil {
+		return nil, fmt.Errorf("error finding user by email: %w", err)
+	}
+	return &OwnerEvaluation{
+		Owner: *principal.ToPrincipalInfo(),
+	}, nil
+}
+
 func (s *Service) Validate(
 	ctx context.Context,
 	repo *types.Repository,
@@ -353,6 +428,10 @@ func (s *Service) Validate(
 	for _, entry := range codeowners.Entries {
 		// check for users in file
 		for _, owner := range entry.Owners {
+			// todo: handle usergroup better
+			if strings.HasPrefix(owner, userGroupPrefixMarker) {
+				continue
+			}
 			_, err := s.principalStore.FindByEmail(ctx, owner)
 			if errors.Is(err, gitness_store.ErrResourceNotFound) {
 				codeOwnerValidation.Addf(enum.CodeOwnerViolationCodeUserNotFound,
@@ -381,12 +460,14 @@ func (s *Service) Validate(
 	return &codeOwnerValidation, nil
 }
 
-func flattenReviewers(reviewers []*types.PullReqReviewer) map[string]*types.PullReqReviewer {
-	r := make(map[string]*types.PullReqReviewer)
+func findReviewerInList(email string, uid string, reviewers []*types.PullReqReviewer) *types.PullReqReviewer {
 	for _, reviewer := range reviewers {
-		r[reviewer.Reviewer.Email] = reviewer
+		if uid == reviewer.Reviewer.UID || email == reviewer.Reviewer.Email {
+			return reviewer
+		}
 	}
-	return r
+
+	return nil
 }
 
 // We match a pattern list against a target
diff --git a/app/services/codeowners/wire.go b/app/services/codeowners/wire.go
index ebac1cf03..d3b361ebd 100644
--- a/app/services/codeowners/wire.go
+++ b/app/services/codeowners/wire.go
@@ -15,6 +15,7 @@
 package codeowners
 
 import (
+	"github.com/harness/gitness/app/services/usergroup"
 	"github.com/harness/gitness/app/store"
 	"github.com/harness/gitness/git"
 
@@ -30,6 +31,7 @@ func ProvideCodeOwners(
 	repoStore store.RepoStore,
 	config Config,
 	principalStore store.PrincipalStore,
+	userGroupResolver usergroup.Resolver,
 ) *Service {
-	return New(repoStore, git, config, principalStore)
+	return New(repoStore, git, config, principalStore, userGroupResolver)
 }
diff --git a/app/services/protection/verify_pullreq.go b/app/services/protection/verify_pullreq.go
index ef1d10f1c..d75d4072d 100644
--- a/app/services/protection/verify_pullreq.go
+++ b/app/services/protection/verify_pullreq.go
@@ -108,7 +108,7 @@ func (v *DefPullReq) MergeVerify(
 
 	if v.Approvals.RequireCodeOwners {
 		for _, entry := range in.CodeOwners.EvaluationEntries {
-			reviewDecision, approvers := getCodeOwnerApprovalStatus(entry.OwnerEvaluations)
+			reviewDecision, approvers := getCodeOwnerApprovalStatus(entry)
 
 			if reviewDecision == enum.PullReqReviewDecisionPending {
 				violations.Addf(codePullReqApprovalReqCodeOwnersNoApproval,
@@ -295,10 +295,12 @@ func (v *DefPullReq) Sanitize() error {
 }
 
 func getCodeOwnerApprovalStatus(
-	ownerStatus []codeowners.OwnerEvaluation,
+	entry codeowners.EvaluationEntry,
 ) (enum.PullReqReviewDecision, []codeowners.OwnerEvaluation) {
 	approvers := make([]codeowners.OwnerEvaluation, 0)
-	for _, o := range ownerStatus {
+
+	// users
+	for _, o := range entry.OwnerEvaluations {
 		if o.ReviewDecision == enum.PullReqReviewDecisionChangeReq {
 			return enum.PullReqReviewDecisionChangeReq, nil
 		}
@@ -306,6 +308,19 @@ func getCodeOwnerApprovalStatus(
 			approvers = append(approvers, o)
 		}
 	}
+
+	// usergroups
+	for _, u := range entry.UserGroupOwnerEvaluations {
+		for _, o := range u.Evaluations {
+			if o.ReviewDecision == enum.PullReqReviewDecisionChangeReq {
+				return enum.PullReqReviewDecisionChangeReq, nil
+			}
+			if o.ReviewDecision == enum.PullReqReviewDecisionApproved {
+				approvers = append(approvers, o)
+			}
+		}
+	}
+
 	if len(approvers) > 0 {
 		return enum.PullReqReviewDecisionApproved, approvers
 	}
diff --git a/app/services/usergroup/service.go b/app/services/usergroup/resolver.go
similarity index 73%
rename from app/services/usergroup/service.go
rename to app/services/usergroup/resolver.go
index 984a7a26b..078188dcd 100644
--- a/app/services/usergroup/service.go
+++ b/app/services/usergroup/resolver.go
@@ -17,14 +17,19 @@ package usergroup
 import (
 	"context"
 
-	"github.com/harness/gitness/store"
 	"github.com/harness/gitness/types"
 )
 
-type Service struct {
+var _ Resolver = (*GitnessResolver)(nil)
+
+type GitnessResolver struct {
 }
 
-func (s *Service) Resolve(context.Context, string) (*types.UserGroup, error) {
-	// todo: implement once usergroup is supported
-	return nil, store.ErrResourceNotFound
+func NewGitnessResolver() *GitnessResolver {
+	return &GitnessResolver{}
+}
+
+func (s *GitnessResolver) Resolve(context.Context, string) (*types.UserGroup, error) {
+	// todo: implement once usergroup is supported
+	return nil, ErrNotFound
 }
diff --git a/app/services/usergroup/user_group_resolver.go b/app/services/usergroup/user_group_resolver.go
index dcd3c61da..d63851a1f 100644
--- a/app/services/usergroup/user_group_resolver.go
+++ b/app/services/usergroup/user_group_resolver.go
@@ -16,10 +16,13 @@ package usergroup
 
 import (
 	"context"
+	"errors"
 
 	"github.com/harness/gitness/types"
 )
 
+var ErrNotFound = errors.New("usergroup not found")
+
 type Resolver interface {
 	Resolve(ctx context.Context, scopedID string) (*types.UserGroup, error)
 }
diff --git a/app/services/usergroup/wire.go b/app/services/usergroup/wire.go
new file mode 100644
index 000000000..fc937c612
--- /dev/null
+++ b/app/services/usergroup/wire.go
@@ -0,0 +1,28 @@
+// Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package usergroup
+
+import (
+	"github.com/google/wire"
+)
+
+// WireSet provides a wire set for this package.
+var WireSet = wire.NewSet(
+	ProvideUserGroupResolver,
+)
+
+func ProvideUserGroupResolver() Resolver {
+	return NewGitnessResolver()
+}
diff --git a/cmd/gitness/wire.go b/cmd/gitness/wire.go
index 75bad0f59..7c97bbe07 100644
--- a/cmd/gitness/wire.go
+++ b/cmd/gitness/wire.go
@@ -59,6 +59,7 @@ import (
 	"github.com/harness/gitness/app/services/protection"
 	pullreqservice "github.com/harness/gitness/app/services/pullreq"
 	"github.com/harness/gitness/app/services/trigger"
+	"github.com/harness/gitness/app/services/usergroup"
 	"github.com/harness/gitness/app/services/webhook"
 	"github.com/harness/gitness/app/sse"
 	"github.com/harness/gitness/app/store"
@@ -164,6 +165,7 @@ func initSystem(ctx context.Context, config *types.Config) (*cliserver.System, e
 		cliserver.ProvideKeywordSearchConfig,
 		keywordsearch.WireSet,
 		controllerkeywordsearch.WireSet,
+		usergroup.WireSet,
 	)
 	return &cliserver.System{}, nil
 }
diff --git a/cmd/gitness/wire_gen.go b/cmd/gitness/wire_gen.go
index 075ab6f2d..9d6d7ba37 100644
--- a/cmd/gitness/wire_gen.go
+++ b/cmd/gitness/wire_gen.go
@@ -58,6 +58,7 @@ import (
 	"github.com/harness/gitness/app/services/protection"
 	"github.com/harness/gitness/app/services/pullreq"
 	trigger2 "github.com/harness/gitness/app/services/trigger"
+	"github.com/harness/gitness/app/services/usergroup"
 	"github.com/harness/gitness/app/services/webhook"
 	"github.com/harness/gitness/app/sse"
 	"github.com/harness/gitness/app/store"
@@ -161,7 +162,8 @@ func initSystem(ctx context.Context, config *types.Config) (*server.System, erro
 		return nil, err
 	}
 	codeownersConfig := server.ProvideCodeOwnerConfig(config)
-	codeownersService := codeowners.ProvideCodeOwners(gitInterface, repoStore, codeownersConfig, principalStore)
+	resolver := usergroup.ProvideUserGroupResolver()
+	codeownersService := codeowners.ProvideCodeOwners(gitInterface, repoStore, codeownersConfig, principalStore, resolver)
 	eventsConfig := server.ProvideEventsConfig(config)
 	eventsSystem, err := events.ProvideSystem(eventsConfig, universalClient)
 	if err != nil {
diff --git a/types/codeowners.go b/types/codeowners.go
index 08b05ac4f..7b30befd8 100644
--- a/types/codeowners.go
+++ b/types/codeowners.go
@@ -26,8 +26,15 @@ type CodeOwnerEvaluation struct {
 }
 
 type CodeOwnerEvaluationEntry struct {
-	Pattern          string            `json:"pattern"`
-	OwnerEvaluations []OwnerEvaluation `json:"owner_evaluations"`
+	Pattern                   string                     `json:"pattern"`
+	OwnerEvaluations          []OwnerEvaluation          `json:"owner_evaluations"`
+	UserGroupOwnerEvaluations []UserGroupOwnerEvaluation `json:"user_group_owner_evaluations"`
+}
+
+type UserGroupOwnerEvaluation struct {
+	ID          string            `json:"id"`
+	Name        string            `json:"name"`
+	Evaluations []OwnerEvaluation `json:"evaluations"`
 }
 
 type OwnerEvaluation struct {