Kalou follows Didier Drogba, Ashley Cole and John Terry in pledging his future to the Premier League outfit.
He has often been used as a substitute since his move to west London, with five of his 10 appearances this season coming off the bench. In total he has made 93 starts and 66 substitute appearances for Chelsea, scoring 31 goals.
Ancelotti added: "Salomon is always well motivated and works hard at his game. Because of this, I'm sure he will become an even more important player for us in the future."
Kalou is likely to play at next summer's World Cup finals after the Ivory Coast sealed their qualification with a 1-1 draw against Malawi on Saturday.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.