Keye was born in the Canton province of China and often referred to himself as a "Cantonese Ham." His family moved to Seattle, Washington when he was still a toddler and he grew up there.
He studied at Washington University in Seattle and majored in commercial art, which led to his entering the film business designing movie posters, then as a technical advisor on several Asian-centered films. It was during this time he was cast in his first part, in the film "The Painted Veil." (1934)
It was his being cast as Chinese characters that led to his taking on the role of "Number One Son" Lee Chan in the Charlie Chan films, of which he did throughout the 1930s and 40s. In the 40s he was also cast in the original Green Hornet serials as Kato, and then went on to star opposite Van Johnson in his "Dr. Gillespie" series of films.
In the 1950s his television career began to take off, though he still found time to appear in several movies as well as playing the role of the character he created, Master Wang, in the original Broadway production of the Rodgers and Hammerstein musical "Flower Drum Song," playing the role for two years in New York and another two on the road without ever missing a single performance. He also found time to do English-dubbing for several Japanese monster films, ones with Godzilla and Rodan. This would foreshadow his later vocal talent career, for cartoon voices.
Throughout the 1960s, Keye continued building his profile on television making many appearances in top-rated and popular shows such as "I, Spy," "The FBI," "Hawaii Five-0," "Dragnet 1967," and "Star Trek." It was also during this time he landed his first starring vocal role in the series "Space Ghost," as Brak.
By the time of the 1970s, Keye was a well-known face around television, and it was this that led to his being cast in his most recognizable role, aside from Lee Chan, as Master Po, on the "Kung Fu" series. He played this in addition to doing two other series at the time, "The Amazing Chan And The Chan Clan" for which he was a vocal talent, and "Anna And The King," in 1972. At the close of the decade he worked more on his voice-over parts, most notably as Zoltar in "Battle Of The Planets."
In the 1980s, Keye was declining in health but still made numerous tv appearances, including reprising his role as Master Po in "Kung Fu, The Movie"(1986) as well as more voice-overs.
His final roles were movie parts, as he had begun, and he died at the age of 86, of a stroke, having lived a full life and leaving behind him a legacy of memorable performances.