Baron St Just

{{short description|Extinct barony in the Peerage of the United Kingdom}}

{{Use dmy dates|date=April 2022}}

Baron St Just, of St Just in Penwith, County of Cornwall, was a title in the Peerage of the United Kingdom.{{London Gazette |issue=34176 |date=2 July 1935 |page=4241}} It was created in 1935 for the banker Edward Grenfell. He was the son of Henry Grenfell, the grandson of Charles Grenfell, the great-grandson of Pascoe Grenfell and the first cousin of William Grenfell, 1st Baron Desborough. The title became extinct upon the death of his son, the second Baron, in 1984.

==Barons St Just (1935)==

• Edward Charles Grenfell, 1st Baron St Just (1870–1941)
• Peter George Grenfell, 2nd Baron St Just (1922–1984)