diff --git a/changelog/unreleased/ocs-share-api-userid.md b/changelog/unreleased/ocs-share-api-userid.md
new file mode 100644
index 00000000000..e29fd18ad21
--- /dev/null
+++ b/changelog/unreleased/ocs-share-api-userid.md
@@ -0,0 +1,6 @@
+Change: return the users username instead of the uuid in share responses
+
+A while ago we decided to use the users uuid only internally and to only display or return the users username.
+The ocs share api did still return the uuid.
+
+https://github.com/owncloud/ocis/issues/990
diff --git a/internal/http/services/owncloud/ocs/conversions/main.go b/internal/http/services/owncloud/ocs/conversions/main.go
index 4f74d924cf8..f5375b0f83e 100644
--- a/internal/http/services/owncloud/ocs/conversions/main.go
+++ b/internal/http/services/owncloud/ocs/conversions/main.go
@@ -28,7 +28,9 @@ import (
 
 	"github.com/cs3org/reva/pkg/publicshare"
 	"github.com/cs3org/reva/pkg/user"
+	"github.com/pkg/errors"
 
+	gatewayv1beta1 "github.com/cs3org/go-cs3apis/cs3/gateway/v1beta1"
 	userpb "github.com/cs3org/go-cs3apis/cs3/identity/user/v1beta1"
 	collaboration "github.com/cs3org/go-cs3apis/cs3/sharing/collaboration/v1beta1"
 	link "github.com/cs3org/go-cs3apis/cs3/sharing/link/v1beta1"
@@ -273,15 +275,38 @@ func AsCS3Permissions(p int, rp *provider.ResourcePermissions) *provider.Resourc
 	return rp
 }
 
+// UserServiceUserIDResolver returns a userId resolver using the UserService
+func UserServiceUserIDResolver(ctx context.Context, client gatewayv1beta1.GatewayAPIClient) func(*userpb.UserId) (string, error) {
+	return func(id *userpb.UserId) (string, error) {
+		resp, err := client.GetUser(ctx, &userpb.GetUserRequest{UserId: id})
+		if err != nil {
+			return "", err
+		}
+		return resp.GetUser().GetUsername(), nil
+	}
+}
+
 // UserShare2ShareData converts a cs3api user share into shareData data model
 // TODO(jfd) merge userShare2ShareData with publicShare2ShareData
-func UserShare2ShareData(ctx context.Context, share *collaboration.Share) (*ShareData, error) {
+func UserShare2ShareData(ctx context.Context, share *collaboration.Share, userIDResolver func(*userpb.UserId) (string, error)) (*ShareData, error) {
+	creator, err := userIDResolver(share.GetCreator())
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not resolve user for id: %s", share.GetCreator())
+	}
+	owner, err := userIDResolver(share.GetOwner())
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not resolve user for id: %s", share.GetOwner())
+	}
+	grantee, err := userIDResolver(share.GetGrantee().GetId())
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not resolve user for id: %s", share.GetGrantee().GetId())
+	}
 	sd := &ShareData{
 		Permissions:  UserSharePermissions2OCSPermissions(share.GetPermissions()),
 		ShareType:    ShareTypeUser,
-		UIDOwner:     LocalUserIDToString(share.GetCreator()),
-		UIDFileOwner: LocalUserIDToString(share.GetOwner()),
-		ShareWith:    LocalUserIDToString(share.GetGrantee().GetId()),
+		UIDOwner:     creator,
+		UIDFileOwner: owner,
+		ShareWith:    grantee,
 	}
 
 	if share.Id != nil && share.Id.OpaqueId != "" {
@@ -297,14 +322,21 @@ func UserShare2ShareData(ctx context.Context, share *collaboration.Share) (*Shar
 }
 
 // PublicShare2ShareData converts a cs3api public share into shareData data model
-func PublicShare2ShareData(share *link.PublicShare, r *http.Request, publicURL string) *ShareData {
+func PublicShare2ShareData(share *link.PublicShare, r *http.Request, publicURL string, userIDResolver func(*userpb.UserId) (string, error)) (*ShareData, error) {
 	var expiration string
 	if share.Expiration != nil {
 		expiration = timestampToExpiration(share.Expiration)
 	} else {
 		expiration = ""
 	}
-
+	creator, err := userIDResolver(share.GetCreator())
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not resolve user for id: %s", share.GetCreator())
+	}
+	owner, err := userIDResolver(share.GetOwner())
+	if err != nil {
+		return nil, errors.Wrapf(err, "could not resolve user for id: %s", share.GetOwner())
+	}
 	sd := &ShareData{
 		// share.permissions are mapped below
 		// Displaynames are added later
@@ -318,8 +350,8 @@ func PublicShare2ShareData(share *link.PublicShare, r *http.Request, publicURL s
 		MailSend:     0,
 		URL:          publicURL + path.Join("/", "#/s/"+share.Token),
 		Permissions:  publicSharePermissions2OCSPermissions(share.GetPermissions()),
-		UIDOwner:     LocalUserIDToString(share.Creator),
-		UIDFileOwner: LocalUserIDToString(share.Owner),
+		UIDOwner:     creator,
+		UIDFileOwner: owner,
 	}
 
 	if share.PasswordProtected {
@@ -327,19 +359,11 @@ func PublicShare2ShareData(share *link.PublicShare, r *http.Request, publicURL s
 		sd.ShareWithDisplayname = "***redacted***"
 	}
 
-	return sd
+	return sd, nil
 	// actually clients should be able to GET and cache the user info themselves ...
 	// TODO check grantee type for user vs group
 }
 
-// LocalUserIDToString transforms a cs3api user id into an ocs data model without domain name
-func LocalUserIDToString(userID *userpb.UserId) string {
-	if userID == nil || userID.OpaqueId == "" {
-		return ""
-	}
-	return userID.OpaqueId
-}
-
 // UserIDToString transforms a cs3api user id into an ocs data model
 // TODO This should be used instead of LocalUserIDToString bit it requires interpreting an @ on the client side
 // TODO An alternative would be to send the idp / iss as an additional attribute. might be less intrusive
diff --git a/internal/http/services/owncloud/ocs/handlers/apps/sharing/shares/public.go b/internal/http/services/owncloud/ocs/handlers/apps/sharing/shares/public.go
index 86a5b6dd2bf..ac43ffa1a56 100644
--- a/internal/http/services/owncloud/ocs/handlers/apps/sharing/shares/public.go
+++ b/internal/http/services/owncloud/ocs/handlers/apps/sharing/shares/public.go
@@ -148,7 +148,11 @@ func (h *Handler) createPublicLinkShare(w http.ResponseWriter, r *http.Request)
 		return
 	}
 
-	s := conversions.PublicShare2ShareData(createRes.Share, r, h.publicURL)
+	s, err := conversions.PublicShare2ShareData(createRes.Share, r, h.publicURL, conversions.UserServiceUserIDResolver(ctx, c))
+	if err != nil {
+		response.WriteOCSError(w, r, response.MetaServerError.StatusCode, "error enhancing response with share data", err)
+		return
+	}
 	err = h.addFileInfo(ctx, s, statRes.Info)
 	if err != nil {
 		response.WriteOCSError(w, r, response.MetaServerError.StatusCode, "error enhancing response with share data", err)
@@ -199,7 +203,10 @@ func (h *Handler) listPublicShares(r *http.Request, filters []*link.ListPublicSh
 				continue
 			}
 
-			sData := conversions.PublicShare2ShareData(share, r, h.publicURL)
+			sData, err := conversions.PublicShare2ShareData(share, r, h.publicURL, conversions.UserServiceUserIDResolver(ctx, c))
+			if err != nil {
+				return nil, nil, errors.Wrap(err, "could not convert share to share data")
+			}
 
 			sData.Name = share.DisplayName
 
@@ -425,7 +432,12 @@ func (h *Handler) updatePublicShare(w http.ResponseWriter, r *http.Request, shar
 		return
 	}
 
-	s := conversions.PublicShare2ShareData(publicShare, r, h.publicURL)
+	s, err := conversions.PublicShare2ShareData(publicShare, r, h.publicURL, conversions.UserServiceUserIDResolver(r.Context(), gwC))
+	if err != nil {
+		response.WriteOCSError(w, r, response.MetaServerError.StatusCode, "error enhancing response with share data", err)
+		return
+	}
+
 	err = h.addFileInfo(r.Context(), s, statRes.Info)
 	if err != nil {
 		response.WriteOCSError(w, r, response.MetaServerError.StatusCode, "error enhancing response with share data", err)
diff --git a/internal/http/services/owncloud/ocs/handlers/apps/sharing/shares/shares.go b/internal/http/services/owncloud/ocs/handlers/apps/sharing/shares/shares.go
index 5b30f45579b..a84abc341b1 100644
--- a/internal/http/services/owncloud/ocs/handlers/apps/sharing/shares/shares.go
+++ b/internal/http/services/owncloud/ocs/handlers/apps/sharing/shares/shares.go
@@ -302,7 +302,7 @@ func (h *Handler) createUserShare(w http.ResponseWriter, r *http.Request) {
 		response.WriteOCSError(w, r, response.MetaServerError.StatusCode, "grpc create share request failed", err)
 		return
 	}
-	s, err := conversions.UserShare2ShareData(ctx, createShareResponse.Share)
+	s, err := conversions.UserShare2ShareData(ctx, createShareResponse.Share, conversions.UserServiceUserIDResolver(ctx, c))
 	if err != nil {
 		response.WriteOCSError(w, r, response.MetaServerError.StatusCode, "error mapping share data", err)
 		return
@@ -451,7 +451,11 @@ func (h *Handler) getShare(w http.ResponseWriter, r *http.Request, shareID strin
 	*/
 
 	if err == nil && psRes.GetShare() != nil {
-		share = conversions.PublicShare2ShareData(psRes.Share, r, h.publicURL)
+		share, err = conversions.PublicShare2ShareData(psRes.Share, r, h.publicURL, conversions.UserServiceUserIDResolver(ctx, client))
+		if err != nil {
+			response.WriteOCSError(w, r, response.MetaServerError.StatusCode, "error mapping share data", err)
+			return
+		}
 		resourceID = psRes.Share.ResourceId
 	}
 
@@ -486,7 +490,7 @@ func (h *Handler) getShare(w http.ResponseWriter, r *http.Request, shareID strin
 
 		if err == nil && uRes.GetShare() != nil {
 			resourceID = uRes.Share.ResourceId
-			share, err = conversions.UserShare2ShareData(ctx, uRes.Share)
+			share, err = conversions.UserShare2ShareData(ctx, uRes.Share, conversions.UserServiceUserIDResolver(ctx, client))
 			if err != nil {
 				response.WriteOCSError(w, r, response.MetaServerError.StatusCode, "error mapping share data", err)
 				return
@@ -614,7 +618,7 @@ func (h *Handler) updateShare(w http.ResponseWriter, r *http.Request, shareID st
 		return
 	}
 
-	share, err := conversions.UserShare2ShareData(ctx, gRes.Share)
+	share, err := conversions.UserShare2ShareData(ctx, gRes.Share, conversions.UserServiceUserIDResolver(ctx, uClient))
 	if err != nil {
 		response.WriteOCSError(w, r, response.MetaServerError.StatusCode, "error mapping share data", err)
 		return
@@ -793,7 +797,7 @@ func (h *Handler) listSharesWithMe(w http.ResponseWriter, r *http.Request) {
 			info = statRes.GetInfo()
 		}
 
-		data, err := conversions.UserShare2ShareData(r.Context(), rs.Share)
+		data, err := conversions.UserShare2ShareData(r.Context(), rs.Share, conversions.UserServiceUserIDResolver(ctx, gwc))
 		if err != nil {
 			log.Debug().Interface("share", rs.Share).Interface("shareData", data).Err(err).Msg("could not UserShare2ShareData, skipping")
 			continue
diff --git a/internal/http/services/owncloud/ocs/handlers/apps/sharing/shares/user.go b/internal/http/services/owncloud/ocs/handlers/apps/sharing/shares/user.go
index e08b57d508d..ef3b906c279 100644
--- a/internal/http/services/owncloud/ocs/handlers/apps/sharing/shares/user.go
+++ b/internal/http/services/owncloud/ocs/handlers/apps/sharing/shares/user.go
@@ -94,7 +94,7 @@ func (h *Handler) listUserShares(r *http.Request, filters []*collaboration.ListS
 
 		// build OCS response payload
 		for _, s := range lsUserSharesResponse.Shares {
-			data, err := conversions.UserShare2ShareData(ctx, s)
+			data, err := conversions.UserShare2ShareData(ctx, s, conversions.UserServiceUserIDResolver(ctx, c))
 			if err != nil {
 				log.Debug().Interface("share", s).Interface("shareData", data).Err(err).Msg("could not UserShare2ShareData, skipping")
 				continue