Reeves was born in Beirut, Lebanon, the son of Patricia Bond (née Taylor), an English-born costume designer/performer, and Samuel Nowlin Reeves, Jr. His father, who is a Hawaiian-born American, has English, Native Hawaiian, Chinese, Irish, and Portuguese ancestry.
Reeves began his acting career at the age of nine, appearing in a theater production of Damn Yankees. At 15, he played Mercutio in a stage production of Romeo and Juliet at the Leah Posluns Theater. Reeves made his screen acting debut in a CBC Television comedy series entitled Hangin' In. In the early 1980s, he appeared in commercials (including one for Coca-Cola), short films including the NFB drama One Step Away and stage work such as Brad Fraser's cult hit Wolfboy in Toronto. In 1984, he was a correspondent for the Canadian Broadcasting Corporation TV youth program Going Great.
The 1999 science fiction-action hit The Matrix, a film in which Reeves had a starring role, was a box office success and attracted positive reviews. In between the first Matrix film and its sequels, Reeves received positive reviews for his portrayal of an abusive husband in The Gift. Aside from The Gift, Reeves appeared in several films that received mostly negative reviews and unimpressive box office grosses, including The Watcher, Sweet November and The Replacements. However, the two Matrix sequels, The Matrix Reloaded and The Matrix Revolutions, along with Something's Gotta Give and the 2005 horror-action film, Constantine, proved to be box office successes and brought Reeves back into the public spotlight.
Reeves is a U.S. citizen through his American father and also holds Canadian citizenship by naturalization; he grew up as a Canadian and identifies as such. He is also entitled to British citizenship through his English mother.
During his initial rise to stardom, Reeves preferred to live in rental houses and hotels. He was also a long-term resident of the Chateau Marmont. However, around 2003, Reeves bought his first house in the Hollywood Hills of Los Angeles. He has since purchased an apartment in Central Park West, New York City.