| Close Other Tabs By Double Click | | - | | |
| Close Other Tabs Button | | - | | |
| Close Other Tabs | | - | | |
| Close Multiple tabs! | | - | | |
| Close Button | | - | | |
| Close All the Tabs | | - | | |
| Close All Tabs Button (913236) | | - | | |
| Close All Tabs Button | | - | | |
| Close All Tabs (Reloaded) | | - | | |
| Clone Tab | | - | | |
| Clone It | | - | | |
| CloSelecTab | | - | | |
| Clip title url active tab | | - | | |
| ClickTabUniq | | - | | |
| ClickTabSort | | - | | |
| ClickTabMove | | - | | |
| ClearWebStats Site Report | | - | | |
| ClearSearch | | - | | |
| Clear Tabs | | - | | |
| Clear Search Bar Text On Search | | - | | |
| Clear Search 2 | | - | | |
| Clear New Tab | | - | | |
| Clear Fields | | - | | |
| CleanupTabs | | - | | |
| Classical Search Bar | | - | | |
| Classic Toolbar Buttons | | - | | |
| Classic Theme Restorer | | - | | |
| Classic Style for Favicons | | - | | |
| Classic Reload-Stop-Go Button | | - | | |
| Classic Opera | | - | | |
| Classic Newtab Restored | | - | | |
| Classic Compact Options | | - | | |
| Change Default Search Engine | | - | | |
| CaretTab - New Tab Clock and Date | | - | | |
| Candy Tabs | | - | | |
| CLUT： Cycle Last Used Tabs | | - | | |
| Bynames | | - | | |
| Buttons Back | | - | | |
| Bug 566510 - Allow multiselect operations on tabs | | - | | |
| Browse Later | | - | | |
| Browse By Name | | - | | |
| Bottom UI | | - | | |
| Bottom Tabs | | - | | |
| BookmarksDropDown | | - | | |
| Bookmarks toolbar toggle button | | - | | |
| Bookmarks menu | | - | | |
| Bookmarks Toolbar Restyled | | - | | |
| Bookmarks Toolbar Keyboard Navigation | | - | | |
| Bookmarks Sidebar Scroll Retainer | | - | | |
| Bookmarks Sidebar Button | | - | | |