Alan Lake was born in Stoke-on-Trent, Staffordshire on 24 November 1940. He studied acting at RADA, and began to work in television roles in 1964.

He is best known as the third husband of the Actress Diana Dors, whom he met on the set of the 1968 television series The Inquisitors. He was initially not keen on Dors; his reaction on finding that he would be working with her was, "Oh no, not Madame Tits and Lips!", but within days, they had fallen in love and were married on 23 November 1968. Their stormy marriage produced a son, Jason David, born in 1969. The pair worked together in the early 1970s, on stage in plays such as Three Months Gone, in which Dors received her best critical reviews since Yield to the Night, and they also received an offer to appear together in a TV sitcom, Queenie's Castle.

A lesser known fact is that he recorded a pop single, "Good Times"/"Got To Have Tenderness" issued in 1969 by Ember Records (EMBS 278)., the former a cover of a song written by Harry Nilsson.

In July 1970, Lake was involved in a pub brawl for which he was sentenced to 18 months in prison later that year (his friend, the musician Leapy Lee, was sentenced to three years for stabbing the pub's relief manager), although he was released after serving a year. Lake was a keen horseman and on his release from prison, Dors presented him with a mare named Sapphire. While riding the horse in 1972, he was unseated when the horse ran into the bough of a tree, and broke his back, and for a time it was thought he might spend the rest of his life in a wheelchair; in fact, he recovered and was walking again within three weeks. After leaving hospital, unable to work while he recovered, and in severe pain, he began drinking heavily. Dors said of him at this time: "alcohol had unleashed a Monster, uncontrollable and frightening".

Lake began hallucinating and lapsing into psychotic episodes, but was diverted from drinking after becoming a Roman Catholic, also convincing Dors to follow him in adopting the religion. In 1974, Dors was rushed to hospital suffering from meningitis, and Lake was told that she might not survive the night, causing him to faint. In 1975, within months of her illness, Dors became pregnant at the age of 43 with their second child and was advised by doctors to have an abortion, but because of her new-found religion, and regret at two previous abortions, decided to go ahead with the pregnancy. She miscarried, which led Lake to return to heavy drinking.

Lake's once promising acting career was now reduced for the remainder of the 1970s to small parts in low-budget comedy films and television dramas, although he had a significant role as a singer Jack Daniels in the Slade vehicle Slade In Flame in 1974 and also as John Merrick in the first episode of the hugely popular TV series The Sweeney. Both he Dors attended the film premiere at the Metropole Theatre, Victoria, London, on 13 February 1975.

In 1980, the pair separated for a time, although they were reconciled when Lake promised to undergo treatment for his alcoholism. Acting work became less frequent for Lake in the 1980s, and Dors's health began to deteriorate – she was first diagnosed with cancer in 1982. In May 1984, Dors died after a long battle with ovarian cancer. Lake immediately burnt all of Dors' clothes, and then fell into a depression. On 10 October 1984, after taking their son to the railway station, he returned to their Sunningdale home and took his own life by shooting himself in the head in their son's bedroom, five months after Dors's death from cancer and 16 years to the day since they had first met; He was 43.