He is best known for his roles as Bill Hooten in Guestward, Ho!, as Jim Nash in the Please Don't Eat the Daisies TV series and as Alvie in the movie he wrote and produced, Savannah Smiles.

After graduation he was immediately cast in the revival of The Philadelphia Story in Newport, Rhode Island, at the Casino Playhouse and began a long-lasting career acting on stage and in television.

He co-starred with Joanne Dru and J. Carrol Naish in the 1960–61 ABC sitcom Guestward, Ho!, the story of a New York City family named "Hooten" who relocates to New Mexico to operate a dude ranch.

Miller guest-starred in numerous series, including NBC's Western The Tall Man, with Barry Sullivan and Clu Gulager.

In 1965-66, he portrayed college professor Jim Nash, the leading role opposite Patricia Crowley, on the NBC-MGM television sitcom Please Don't Eat the Daisies, loosely based on the theatrical film starring Doris Day and David Niven.

In 2014, he moved back to Los Angeles, where he formed the production company Gypsy Moon Entertainment, and he continued to write and sell screenplays.