Michael Sellers was Peter Sellers' son from his first marriage to former actress Anne Howe. Growing up was difficult for Michael as he frequently witnessed his parents quarrelling and he described his father's temper as mercurial and irrational. His close friend at prep school (The Hall School, Hampstead) was actor Donald Sinden's son Marc Sinden. When Michael was seven his parents divorced and in an interview Marc Sinden said that Peter Sellers always behaved badly towards Michael. He also recalled seeing some of the letters Michael received from his father and concluded that he was a "really, really nasty man". His mother remarried and his stepfather was a welcome change for Michael. During the school year he stayed with his mother and stepfather, while he spent the school holidays with Peter Sellers. He was whisked along with his sister to international as well as exotic locations depending on the particular purpose his father Peter had in mind. Peter Sellers would visit Rome, for example, because he had developed a romantic interest in Sophia Loren.

Other locations included Monte Carlo, New York and Hollywood. At home they would vacation in Windsor Great Park with Princess Margaret. But Peter Sellers was insecure about his relationship with his son and became vindictive at times going as far as telling his son that he disowned him. On another occasion he suggested that Michael change his last name.

When Peter Sellers married Miranda Quarry he brought Michael to Venice only to leave him there after he and his bride decided to travel somewhere else. The unpredictable father would sometimes ask the children's opinion about his future life partners.

When Michael’s first marriage ended in failure, he became closer with his father as the two started discussing Michael's life problems. This did not last long as Peter Sellers died a few months later. In his will Peter Sellers left Michael about eight hundred pounds from his multi-million pound estate. Michael Sellers also claimed that the eight hundred pounds he received was a calculated act to prevent him from contesting the will, since under English law only complete disinheritance provided the legal grounds for a challenge of the will.

Michael Sellers' film career started early when at age seven he played the role of Gaston in the film Mr. Topaze, directed by his father. As an adult he became a builder and property dealer. He was also a car salesman, musician and writer.

He went on to star in The Life and Legacy of Spike Milligan , a film he did in collaboration with the children of Spike Milligan. He also wrote three biographical books about his father.

Despite his turbulent relationship with his father, he often defended his father's legacy. Upon the release of the 2004 film The Life and Death of Peter Sellers, based on the book of the same name by Roger Lewis, Sellers railed against Lewis and Stephen Hopkins, the film's director. Sellers was incensed at the portrayal of his father as clinically insane. Sellers, at the time, called Roger Lewis' book "400 pages of rubbish". Hopkins responded to Seller's comments when he appeared at the film festival to promote the film, stating that the film was not disrespectful to Peter Sellers.

In 2000 he authored his last book, Sellers On Sellers where he wrote:

Michael Sellers died of the same cause (heart attack) and on the same date, 24 July, twenty six years later, as his father. He was two years younger.