Colonel Herbert Mercer (4 January 1862 – 8 February 1944) was a British Army officer and a Conservative politician and member of parliament in the 1920s.

He was educated at Harrow School and entered Trinity College, Cambridge in 1880.

[3] Mercer was returned as the member of parliament for the Sudbury Division of Suffolk for the 1922 general election.

[4] He lost the seat in the 1923 election to Liberal politician John Frederick Loverseed.

[4] Mercer died on 8 February 1944 at Rotherfield, and was buried at Stradishall.