Donald Ferdinand Kellner (September 15, 1879 – April 1, 1935) was a politician from Alberta, Canada.

He defeated Joseph Clarke and incumbent Henry Arthur Mackie in a 3-way race to serve his first term in office.

Kellner was defeated by former Alberta Liberal MLA Charles Cross.

A year later, in the 1926 Canadian federal election running for the UFA again, he defeated Cross.

Kellner was defeated by John Francis Buckley iwhen he ran for re-election in the 1930 Canadian federal election in the Athabaska district.