The most common reason for the “Downloads” Folder missing on Mac from its usual location on the Dock is due to the Downloads Folder being accidentally deleted by the User.
Similarly, if the Downloads Folder is missing or not appearing in the Finder Sidebar, the reason for this issue is due to “Show Downloads Folder” option not being selected or accidently being unchecked on the Finder Preferences screen.
Restore Missing Downloads Folder on Mac
Even if you had accidentally deleted the Downloads Folder from the Dock, it can be easily added back to Dock on your Mac by using the first method as provided below in this guide.
Similarly, if the Downloads Folder is missing from the Finder Sidebar, it can be brought back by going to Finder Preferences screen and selecting the option to “Show Downloads Folder” on the Finder Sidebar.
1. Restore Missing Downloads Folder on Dock
If the Downloads Folder is missing from the Dock on Mac, it can be Restored back by using the following steps.
1. Open the Finder on your Mac > select the Go tab in the top-menu bar and click on Home in the drop-down menu.

2. On the next screen, locate Downloads Folder and drag it towards the Dock on your Mac.

Do not release Downloads Folder, continue dragging it towards the right of the Dock and drop it to the left of the Trash Can icon.

After this, you should find Downloads Folder back at its Default position in the Dock.
2. Restore Missing Downloads Folder on Finder
You can follow the steps below to restore or bring back the missing Downloads Folder to the Finder Sidebar on your Mac.
1. Open Finder > select the Finder tab in top-menu bar and click on Preferences in the drop-down menu.

2. On the Finder Preferences screen, go to the Sidebar tab and select the Downloads check box.

After this, you should be able to see the Downloads Folder on the Finder Sidebar on your Mac.