As his father's health declined over two years, Donahue began to exhibit behavior issues, including drinking alcohol in excess.

[2] After Donahue dropped out of high school in his sophomore year, his mother enrolled him into the New York Military Academy, where he roomed with English actor Owen Orr.

[7] When Donahue was 18, he moved back to New York and got a job as a messenger for Sound Masters, a commercial film company that his father had founded.

[2] In spring that same year, producer William Asher and director James Sheldon spotted Donahue in a diner in Malibu and arranged for a screen test with Columbia Pictures.

The weekend before the big meeting, Donahue suffered a near-fatal auto accident, plummeting 40 feet down into a canyon and smashing into a tree.

Willson was able to secure guest starring roles in several western shows, allowing Donahue to rent a slightly smaller apartment in Hollywood.

Donahue achieved good reviews for a brief, but effective part in Douglas Sirk's Imitation of Life (1959), playing Frankie, a young white man who beats his new girlfriend after he discovers she is black.

[16] The big break of Donahue's career came when he was cast opposite Sandra Dee in the 1959 Warner Bros' film A Summer Place, directed by Delmer Daves.

Journalist Joan Beck wrote in the Chicago Tribune on October 22, 1959:To plug the movie – and sell himself, too – Troy is touring the country with press agents and studio representatives from Warner Bros., to whom he is under contract.

Now that all the proper stops have been pulled out, Hollywood's star makers expect teenagers to respond with a chorus of enthusiasm loud enough to sweep Troy into real movie stardom.

[22]Donahue guest starred in a variety of their western television series, including Colt .45 (1959), Maverick (1959), Sugarfoot (1959), The Alaskans (1960), and Lawman (1960).

On Surfside 6, Donahue starred with Van Williams, Lee Patterson, Diane McBain, and Margarita Sierra in the ABC series, set in Miami Beach, Florida.

Journalist Rick Du Brow wrote of him, "Troy is big and strong and has the rare ability to make the most glamorous and exciting events seem colorless and flat.

"[30] Donahue and Daves reunited for another melodrama in 1961, Susan Slade, with Connie Stevens, Dorothy McGuire and Lloyd Nolan also starring.

[34] Donahue had also gained wide popularity in Japan, later saying[35] "I guess because I was blond, blue-eyed, and tanned, people associated me with all those beach movies that were around then, even though I never did one."

[48][49] This lasted a year and saw him get four roles: guest shots on Ironside (1968), The Name of the Game (1968), and The Virginian (1969), and an appearance in the TV movie The Lonely Profession (1969).

"[2][13] In November 1971, Donahue chopped his hair, shedding his new look, and moved to Atlanta, Georgia to play a cop in Michael Meola's independent film Without Last Rights.

[2] With no upcoming acting jobs, Donahue accepted a celebrity-for-pay engagement to host a mall-wide fashion show at the Lafayette Plaza Shopping Center in Bridgeport, Connecticut on May 26, 1972.

"[56] In the spring of 1973, Donahue traveled to the Philippines to make the low budget gory action film South Sea Massacre.

The movie was criticized for a lack of story and an abundance of nudity, rapes, beatings, decapitations, machete slayings, and machine gun attacks.

In December 1973, Donahue returned to Atlanta to promote and participate in a concert at Omni Coliseum to raise money for the Wounded Knee defense fund.

Donahue assisted the local AIM office to generate publicity for the benefit concert which starred Paul Ortega, a Mescalero Apache.

He acted as the Master of Ceremonies at the show which featured banjo picker John Hartford, actor Burt Reynolds, Doc and Merle Watson, Yoko Ono, several local performers, and Sacheen Little Feather.

Donahue led the celebrity judge panel that included film stars Jane Withers, Janet Blair, and Terry Moore.

[61] Donahue appeared in a supporting role in the 1984 feature film Grandview, U.S.A.[11] On October 6, 1985, he hosted a telethon in Palm Springs to raise money for the American Red Cross Mexican Earthquake Relief Fund.

Meredith would go on to allege that Donahue "stormed into [her] place... and pushed [her] face into a glass covered picture" upon learning she was dating a mutual friend after their break up.

On February 5, 1982, Donahue's addiction problem culminated in an embarrassing incident when he accompanied Julie Newmar to the wrap party for her film, Hysterical.

[2] On February 22, 1968, Arbua Productions, the talent hiring agency for the Pheasant Run Playhouse in Illinois, won a default judgement against him in the amount of $100,000.

The actor was accused of inducing his wife, Valerie Allen, to break a contract with the theater, and walk out with him days before the production, Poor Richard, was scheduled to open.

[45][98][99][100] On August 30, 2001, Donahue suffered a heart attack and was admitted to Saint John's Health Center in Santa Monica, California.