The 1948 Croydon North by-election was a parliamentary by-election held in the British House of Commons constituency of Croydon North on 11 March 1948. The seat had become vacant when the Conservative Member of Parliament Henry Willink had resigned, having held the seat since a by-election in 1940.
The Labour Party candidate was the British politician, diplomat, historian, diarist, novelist, lecturer, journalist, broadcaster, and gardener Harold Nicolson. Formerly a political ally of Oswald Mosley in the New Party before the later turned to Fascism, Nicolson had previously sat in the 1935–1945 parliament as a National Labour MP. These were the followers of former British Prime Minister Ramsay MacDonald who had been expelled from the Labour Party for forming the first National Government with Conservatives and Liberals without consulting them.
The Conservative candidate Fred Harris held the seat for his party with a much increased majority. The seat had only been marginally Conservative in the 1945 election.
Election results.
! scope="col" colspan="2" style="width: 130px"|Party
! scope="col" style="width: 17em"|Candidate
! scope="col" style="width: 5em"|Votes
! scope="col" style="width: 3.5em"|%
! scope="col" style="width: 3.5em"| ;templatestyles src="Template:Tooltip/styles.css" / ;±%
! colspan="3" style="text-align: right; margin-right: 0.5em" | Majority
! colspan="3" style="text-align: right; margin-right: 0.5em" scope=row | Turnout
! colspan="3" style="text-align:right;" scope=row | Registered electors
! style="text-align:right;" | Swing
! scope="col" colspan="2" style="width: 130px"|Party
! scope="col" style="width: 17em"|Candidate
! scope="col" style="width: 5em"|Votes
! scope="col" style="width: 3.5em"|%
! scope="col" style="width: 3.5em"| ;templatestyles src="Template:Tooltip/styles.css" / ;±%
! colspan="3" style="text-align: right; margin-right: 0.5em" | Majority
! colspan="3" style="text-align: right; margin-right: 0.5em" scope=row | Turnout
! colspan="3" style="text-align:right;" scope=row | Registered electors
! style="text-align:right;" | Swing
References.
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