This Scottish Gaelic surname has been exclusively male in the past, with playwright Maxwell Anderson and actor Maxwell Caulfield being the most well-known people with the moniker. It's one of a whole constellation of Max-names popular with parents—Max itself, the imaginative Maxx (used by Scott Hamilton), and Maximilian (Jennifer Lopez and Marc Anthony). Other celeb parents of boy Maxwells include Brad Garrett, Kerry Katona, and Lance Armstrong.
Gender bending has been a growing trend in the celebrisphere, with Mariah Carey and Nick Cannon's daughter Monroe (granted, that was inspired by a very female Marilyn), Brendan Fehr's James, Ziggy Marley's Judah, James Barbour's Hudson, Soleil Moon Fry's Jagger, and Johnny Knoxville's Arlo, to name a few. Sometimes a celebrity switch is enough to permanently tint a name pink; recent examples include Avery, Emerson, Harper and Finley. It's hard to say whether this will happen with Maxwell, but we can picture Max taking off as a nickname for girls, a la Sam and Charlie.
Maxwell Johnson's middle name, Drew, is Jessica Simpson's mother's maiden name, a nice way of incorporating family history.
Photo: Jessica Simpson in Los Angeles via Helga Esteb/Shutterstock.com