David Demerest Aitken (September 5, 1853 – May 26, 1930) was an American lawyer, accountant and politician who served two terms as a U.S. Representative from the state of Michigan from 1893 to 1897.

He taught in a district school of Genesee County from 1871 to 1872 and moved to New Jersey in 1872, where he was employed as a bookkeeper.

He studied law in New York City, was admitted to the bar in 1878, and commenced practice in Flint.

After losing that election to Hazen S. Pingree, Aitken resumed the practice of law and also engaged in banking.

This article incorporates public domain material from the Biographical Directory of the United States Congress