diff --git a/webapp/src/components/sidebar_right/sidebar_right.jsx b/webapp/src/components/sidebar_right/sidebar_right.jsx
index 567527929..5f654f34c 100644
--- a/webapp/src/components/sidebar_right/sidebar_right.jsx
+++ b/webapp/src/components/sidebar_right/sidebar_right.jsx
@@ -4,8 +4,12 @@
 import React from 'react';
 import PropTypes from 'prop-types';
 import Scrollbars from 'react-custom-scrollbars-2';
+import ReactSelect from 'react-select';
+
+import {makeStyleFromTheme} from 'mattermost-redux/utils/theme_utils';
 
 import {RHSStates} from '../../constants';
+import {getStyleForReactSelect} from '@/utils/styles';
 
 import GithubItems from './github_items';
 
@@ -43,6 +47,13 @@ function mapGithubItemListToPrList(gilist) {
     });
 }
 
+function getRepoName(item) {
+    if (item.repository_url) {
+        return item.repository_url.replace(/.+\/repos\//, '');
+    }
+    return item.repository?.full_name ?? null;
+}
+
 function shouldUpdateDetails(prs, prevPrs, targetState, currentState, prevState) {
     if (currentState === targetState) {
         if (currentState !== prevState) {
@@ -81,6 +92,15 @@ export default class SidebarRight extends React.PureComponent {
         }).isRequired,
     };
 
+    constructor(props) {
+        super(props);
+        this.state = {selectedRepo: ''};
+    }
+
+    handleRepoFilterChange = (selectedOption) => {
+        this.setState({selectedRepo: selectedOption ? selectedOption.value : ''});
+    }
+
     componentDidMount() {
         if (this.props.yourPrs && this.props.rhsState === RHSStates.PRS) {
             this.props.actions.getYourPrsDetails(mapGithubItemListToPrList(this.props.yourPrs));
@@ -92,6 +112,22 @@ export default class SidebarRight extends React.PureComponent {
     }
 
     componentDidUpdate(prevProps) {
+        // Reset repo filter when switching RHS tabs
+        if (prevProps.rhsState !== this.props.rhsState) {
+            this.setState({selectedRepo: ''}); // eslint-disable-line react/no-did-update-set-state
+        }
+
+        // Validate selectedRepo against the current list — reset if the repo
+        // is no longer present (stale state when the underlying data changes)
+        if (this.state.selectedRepo) {
+            const currentRepos = [...new Set(
+                this.getCurrentItems().map(getRepoName).filter(Boolean),
+            )];
+            if (!currentRepos.includes(this.state.selectedRepo)) {
+                this.setState({selectedRepo: ''}); // eslint-disable-line react/no-did-update-set-state
+            }
+        }
+
         if (shouldUpdateDetails(this.props.yourPrs, prevProps.yourPrs, RHSStates.PRS, this.props.rhsState, prevProps.rhsState)) {
             this.props.actions.getYourPrsDetails(mapGithubItemListToPrList(this.props.yourPrs));
         }
@@ -101,6 +137,22 @@ export default class SidebarRight extends React.PureComponent {
         }
     }
 
+    getCurrentItems = () => {
+        const {yourPrs, reviews, unreads, yourAssignments, rhsState} = this.props;
+        switch (rhsState) {
+        case RHSStates.PRS:
+            return yourPrs || [];
+        case RHSStates.REVIEWS:
+            return reviews || [];
+        case RHSStates.UNREADS:
+            return unreads || [];
+        case RHSStates.ASSIGNMENTS:
+            return yourAssignments || [];
+        default:
+            return [];
+        }
+    }
+
     render() {
         const baseURL = this.props.enterpriseURL ? this.props.enterpriseURL : 'https://github.com';
         let orgQuery = '';
@@ -134,17 +186,39 @@ export default class SidebarRight extends React.PureComponent {
             githubItems = unreads;
             title = 'Unread Messages';
             listUrl = baseURL + '/notifications';
+
             break;
         case RHSStates.ASSIGNMENTS:
 
             githubItems = yourAssignments;
             title = 'Your Assignments';
             listUrl = baseURL + '/pulls?q=is%3Aopen+archived%3Afalse+assignee%3A' + username + orgQuery;
+
             break;
         default:
             break;
         }
 
+        // Extract unique repo names for filter dropdown
+        const repoNames = [...new Set(
+            githubItems.map(getRepoName).filter(Boolean),
+        )].sort();
+
+        // Build react-select options
+        const repoOptions = [
+            {value: '', label: 'All repositories'},
+            ...repoNames.map((repo) => ({value: repo, label: repo})),
+        ];
+
+        // Filter items by selected repo
+        const {selectedRepo} = this.state;
+        const selectedOption = repoOptions.find((opt) => opt.value === selectedRepo) || repoOptions[0];
+        const filteredItems = selectedRepo ?
+            githubItems.filter((item) => getRepoName(item) === selectedRepo) :
+            githubItems;
+
+        const style = getStyle(this.props.theme);
+
         return (
             <React.Fragment>
                 <Scrollbars
@@ -163,10 +237,24 @@ export default class SidebarRight extends React.PureComponent {
                                 rel='noopener noreferrer'
                             >{title}</a>
                         </strong>
+                        {repoNames.length > 1 && (
+                            <div style={style.repoFilterContainer}>
+                                <ReactSelect
+                                    value={selectedOption}
+                                    onChange={this.handleRepoFilterChange}
+                                    options={repoOptions}
+                                    styles={getStyleForReactSelect(this.props.theme)}
+                                    aria-label='Filter by repository'
+                                    isSearchable={false}
+                                    menuPortalTarget={document.body}
+                                    menuPlacement='auto'
+                                />
+                            </div>
+                        )}
                     </div>
                     <div>
                         <GithubItems
-                            items={githubItems}
+                            items={filteredItems}
                             theme={this.props.theme}
                             showReviewSLA={rhsState === RHSStates.REVIEWS}
                             reviewTargetDays={this.props.reviewTargetDays || 0}
@@ -178,8 +266,16 @@ export default class SidebarRight extends React.PureComponent {
     }
 }
 
-const style = {
-    sectionHeader: {
-        padding: '15px',
-    },
-};
+const getStyle = makeStyleFromTheme((theme) => {
+    return {
+        sectionHeader: {
+            padding: '15px',
+        },
+        repoFilterContainer: {
+            marginLeft: '8px',
+            minWidth: '160px',
+            maxWidth: '220px',
+            fontSize: '12px',
+        },
+    };
+});