The 1938 City of London by-election was a by-election held on 6 April 1938 for the British House of Commons constituency of City of London, which covered the "Square Mile" which was the United Kingdom's traditional financial district.

The by-election was caused by the death of one of the City's two Conservative Party Members of Parliament (MPs) Thomas Vansittart Bowater, who had held the seat since a by-election in 1924, having contested the seat in an earlier by-election in 1922.

The Conservative candidate, Sir George Broadbridge, who had been Lord Mayor of London in 1936, was returned unopposed.^{[citation needed]}

• Craig, F. W. S. (1983) [1969]. British parliamentary election results 1918-1949 (3rd ed.). Chichester: Parliamentary Research Services. ISBN 0-900178-06-X.
• Leigh Rayment's Peerage Pages ^{[self-published source] [better source needed]}

• List of United Kingdom by-elections
• City of London constituency
• 1922 City of London by-election
• 1924 City of London by-election
• 1935 City of London by-election
• 1940 City of London by-election
• 1945 City of London by-election