Galli was born in Venice and was a member of "a typical Italian theatrical family".

She appeared with Clark Gable in They Met in Bombay (1941) and played Christine's maid in The Phantom of the Opera (1943).

The actress also portrayed the friendly wife of J. Carrol Naish in Star in the Night (1945), an Academy-Award-winning short film by Don Siegel.

Through her accent she frequently played motherly characters of Italian or Spanish descent, mostly in small roles.

She also worked as the Italian dubbing voice for actresses like Joan Crawford, Marie Dressler, and Myrna Loy.