Ken Ludwig's first hit play, Lend Me a Tenor, was produced by Andrew Lloyd Webber for the West End in London in 1986 and on Broadway in 1989.

A revival of Lend Me a Tenor opened on Broadway in 2010, starring Tony Shalhoub, Anthony LaPaglia and Jan Maxwell.

His second Broadway and West End production, Crazy for You, is an original musical drawing from the catalogue of George and Ira Gershwin.

The same play, under the title Over the Moon, subsequently ran on London's West End at the Old Vic in 2001 in a production starring Frank Langella and Joan Collins.

In 2011, he adapted Shakespeare's A Midsummer Night's Dream into a contemporary American play for high school and college students titled Midsummer/Jersey.

At the request of the Agatha Christie Estate, Ludwig wrote Murder on the Orient Express, a stage adaptation of the novel of the same name, which premiered at the McCarter Theatre Center in 2017.

[4] In July of the same year, the world premiere of Sherwood: The Adventures of Robin Hood opened at The Old Globe in San Diego as a commission from the theatre.

The Game's Afoot, Ludwig's comedy-mystery about the actor William Gillette, who originated the role of Sherlock Holmes, premiered at the Cleveland Play House in November 2011, and won the 2012 Edgar Allan Poe Award for Best Mystery of the Year.

A new mystery-comedy in the style of Baskerville and Moriarty, titled Lady Molly of Scotland Yard, will premiere in the 2024-25 theatrical season.

The world premiere of his first play for children, Twas The Night Before Christmas, opened at The Adventure Theatre Glen Echo Park, Maryland in November 2011.

Ken Ludwig's first play, Lend Me a Tenor, won two Tony Awards in 1989 and was called "one of the classic comedies of the 20th century" by The Washington Post.

Treasure Island won the 2009 American Alliance for Theatre & Education (AATE) Distinguished Play Award (Category C—Adaptations from existing children's literature primarily for Pre-K and elementary age audiences).

He gives the Annual Ken Ludwig Playwriting Scholarship at the Kennedy Center American College Theater Festival, and he served on the Board of Governors of the Folger Shakespeare Library for ten years.