Marshall, 61, and Williams, who turns 57 this month, starred in the 1976 hit comedy about two single, working women in late 1950s Milwaukee.
Their sidewalk stars were unveiled in a ceremony on Hollywood Boulevard.
"We never got any Emmys, so this is great," Marshall said.
Williams thanked her family and friends and said receiving a star was like living a dream.
The actresses played Laverne DeFazio and Shirley Feeney, who were originally cast as fast girls who dated the characters Fonzie and Richie Cunningham on "Happy Days."
Both "Laverne & Shirley" and "Happy Days" are debuting on DVD this month.
Marshall is now a producer and director whose films include "Big" and "A League of Their Own."
Williams co-produced "Father of the Bride" and its sequel, and has recently appeared on television shows such as "Law & Order" and "Seventh Heaven."