The Stanley Cup champions announced the deals on Monday. The Kings confirmed tentative agreements on both contracts last Friday.
Stoll gets a three-year deal worth $9.75 million, while Fraser has a two-year deal worth $1.65 million.
Stoll and Fraser were key depth forwards during Los Angeles' run to its first championship. Both could have been unrestricted free agents this summer.
Stoll matched his career low with 21 points in the regular season, but played extensive minutes on the Kings' third line and top penalty-killing unit.
Fraser, who played mostly on the fourth line in his first season with Los Angeles, scored the first goal of the Stanley Cup finals against New Jersey.