The actress and longtime boyfriend Dax Shepard tied the knot at the Los Angeles County Clerk in Beverly Hills on Thursday, reports TMZ.
Their intention was to get their marriage license and hold a ceremony on a later date.
A court employee convinced the couple, engaged for four years and seemingly in no hurry, to marry on the spot.
The courtroom wedding was enough for Bell, who previously said she wanted "something sort of private that involves pen and paper."
According to Huffington Post, Bell, 33, and Shepard, 38, held off nuptials until California made same-sex marriage legal.
The newlyweds have a daughter named Lincoln, who was born in March.