Jackson and Lapka wed in the Hamptons, New York, where same-sex marriage was recently legalised.
"It's official, after 11 years together, married the best man I've ever known," Jackson tweeted this weekend, along with a photo of the newlyweds.
The actor is best known for his regular recurring role on NBC comedy 30 Rock as Danny Baker.
More recently, Jackson appeared on Fox musical series Glee as the coach of rival glee club Vocal Adrenaline.
Watch Cheyenne Jackson singing on 30 Rock below: