The intersection between Diane and Michael exists solely inside the legal code of the Screen Actors Guild. Under long-standing SAG name change rules, no two working members can share an identical working moniker. The policy protects artists from stolen residual checks, conflated professional credits, and legal liability.
When Michael Douglas began securing televised work in Los Angeles during the mid-1970s, the union informed him that the name Michael Douglas was already claimed by the future Academy Award winner and son of Kirk Douglas. A daytime talk show host named Mike Douglas was also a prominent household figure. Michael needed an alternate surname immediately.
Legend claimed for decades that he chose "Keaton" after reading an article about Diane Keaton, or out of tribute to silent screen pioneer Buster Keaton. Michael has debunked this folklore repeatedly. Running out of time before a production deadline, he opened a phone book, scrolled to the letter "K," decided "Keaton" sounded unpretentious and plausible, and registered it. In recent years, he has moved toward crediting his work under his full hybrid name, Michael Keaton Douglas.
| Biographical Category | Diane Keaton | Michael Keaton |
|---|---|---|
| Birth Name | Diane Hall | Michael John Douglas |
| Birthplace & Heritage | Los Angeles, CA (English, Irish, German) | Coraopolis, PA (Scottish, Irish, Polish) |
| Parents | Jack Hall & Dorothy Deanne Keaton | George A. Douglas & Leona Elizabeth Pawlak |
| Reason for Alias | Another Diane Hall was registered in Actors' Equity | Michael Douglas was already taken in SAG |
| Source of Surname | Her mother's legal maiden surname | Arbitrary selection from an alphabetical directory |
