Archibald Sinclair, 1st Viscount Thurso (then Sir Archibald Sinclair) was leader of the UK Liberal Party from 1935 until 1945.

{| border="2" align="center" |width="30%" align="center"|Preceded by:
New creation |width="40%" align="center"|Viscount Thurso |width="30%" align="center"|Followed by:
Robin MacDonald Sinclair |}