Romeo Earl Muller, Jr. (August 7, 1928 – December 30, 1992) was an American screenwriter and actor most remembered for his screenplays for the Rankin/Bass Christmas specials including Rudolph the Red-Nosed Reindeer, The Little Drummer Boy, Frosty the Snowman, and Santa Claus Is Coming to Town.

After writing material for comedian Jack Benny, Muller was discovered by CBS founder William S. Paley and selected to be a staff writer for the prestigious Studio One and Philco Theatre.

Rankin and Bass asked Romeo to write a screenplay for their first Network television special, entitled Return to Oz, which aired on NBC's the General Electric Fantasy Hour.

He is also known for his screenplays in other such films as Santa Claus Is Comin' to Town, The Little Drummer Boy, Here Comes Peter Cottontail, and Frosty the Snowman, among many others.

In 2002 the book Jill Chill & the Baron of Glacier Mountain by Ed McCray featured a character named Romeo after Muller.