William Meyers Colmer (February 11, 1890 - September 9, 1980) was a Mississippi politician.

Colmer was born in Moss Point, Mississippi. Colmer attended Millsaps College. He served in the military during World War I.

Colmer was elected Jackson county attorney in1921. In 1928, Colmer was elected district attorney.

In 1932, Colmer was elected to the House of Representatives as a Democrat.

After the Brown v. Board of Education decision, Colmer helped to get Southern congressmen to sign the Southern Manifesto. Using the House Seniority system, Colmer was the chairman of the Rules Committee from 1967 to 1973.

Colmer retired from the House in 1973 and was succeeded by his staffer Trent Lott.