We are not sure exactly who did, but it wasn't a name for a person at first. Chelsea was first used as a district name for a part of London in England. In the Old English dictionary, Chelsea means "landing place for chalk or limestone", meaning it was likely used to describe the stonemason/stone-working areas of London in the past.
It first appeared as a female name in the 1970's, which wasn't that long ago.
Chelsea's real name is Chelsea Kane Staub.
who came up with the name creators
Chelsea Blaine's birth name is Chelsea Shover.
Chelsea Budde's birth name is Chelsea Buchman.
Chelsea McFarland's birth name is Chelsea Austin.
Chelsea Raya's birth name is Chelsea Raya.
Chelsea Renee's birth name is Chelsea Piatetsky.
Chelsea Spear's birth name is Chelsea Kearin.
Chelsea Vincent's birth name is Chelsea Elizabeth Vincent.
Chelsea Peretti's birth name is Chelsea Vanessa Peretti.
Chelsea Makela's birth name is Chelsea Lynn Makela.
Chelsea Logan's birth name is Chelsea Logan Holtzman.