[1] He attended St Edward's School in Oxford, England, and graduated from Temple University in Philadelphia in 1943 with a bachelor's degree in education.

[5][6] Andes began his acting career while serving in the United States Army Air Forces during World War II.

[9] In 1947, Andes received a Theater World Award for his Broadway debut performance in a revival of the operetta The Chocolate Soldier.

Andes, Lex Barker and James Arness played the title character's powerfully built and highly protective brothers.

In June 1950, he joined the cast of Kiss Me, Kate on Broadway, taking over the lead from Alfred Drake, starring in the show for over a year, in New York and on tour.

[11] Andes appeared as Marilyn Monroe's sweetheart and Barbara Stanwyck's brother in the film Clash by Night (1952), directed by Fritz Lang and co-written by Clifford Odets, for RKO.

[15] He co-starred with Angela Lansbury in the film noir A Life at Stake (1954) and was one of several male leads in The Second Greatest Sex (1955) at Universal, where he signed a long-term contract.

He also starred in TV adaptations of The Great Waltz (playing Johann Strauss, Jr.), Bloomer Girl (1956) and Holiday (based on The Grand Tour) (1956).

In 1958, Andes starred as crusading former Louisiana State Police Superintendent Francis Grevemberg in the film Damn Citizen at Universal.

[24] When Wildcat ended Andes resumed his television career, guest starring on Sea Hunt, Have Gun - Will Travel, Follow the Sun, Vacation Playhouse and The Rifleman.

He guest-starred on 77 Sunset Strip, Perry Mason (in the episodes "The Case of the Skeleton's Closet" and "The Case of the Illicit Illusion"), Mickey Rooney's short-lived sitcom Mickey, The Littlest Hobo, Death Valley Days, The Outer Limits, Valentine's Day, Branded, The Lucy Show and Run for Your Life.

He guest-starred on Petticoat Junction, The Bold Ones: The New Doctors, Dan August, The Streets of San Francisco, Search, Gunsmoke, Cannon, Caribe and The Magical World of Disney ("Twister, Bull from the Sky").