In the subsequent free agency period, he signed a one-year contract to return to the Kings, opting for a second tenure with a team for the second time in his career.

Representing Canada internationally on four occasions, Cammalleri won bronze and silver medals at the 2001 and 2002 World Junior Championships respectively.

An all-star in college and the American Hockey League, Cammalleri played in the "Cold War", an outdoor game that set a then world attendance record in 2001.

Cammalleri was born in Richmond Hill, Ontario, and was raised there in a secular household (he described his upbringing as "non-denominational"), but his family background is half-Italian and half-Jewish.

[9] He was named an all-star the following season and was selected as the Ontario Hockey Association's top draft prospect after scoring 103 points in 41 games.

[10] Cammalleri joined the Michigan Wolverines men's ice hockey program in 1999, scoring 13 goals in 39 games as a freshman.

[9] He led the team with 29 goals as a sophomore in 2000–01, and was named a first-team Central Collegiate Hockey Association (CCHA) all-star.

Michigan reached the 2001 Frozen Four, where it lost the National Collegiate Athletic Association (NCAA) semi-final game to Boston College.

[13] At the West Regional tournament, Cammalleri was named both an all-star at forward and the most valuable player as he led Michigan back to the Frozen Four.

[14] Cammalleri chose to forgo his senior year of eligibility, signing a contract with the Kings ahead of the 2002–03 NHL season.

[4] Cammalleri opened the season with 20 goals in his first 22 games en route to a league leading and franchise record setting total of 46.

[9] Returning to Los Angeles in 2005–06, Cammalleri established himself as an NHL regular, appearing in 80 games with the Kings and leading the team with 26 goals.

He improved to 34 goals and 80 points in 2006–07 and was voted the recipient of the Bill Libby Memorial Award as the Kings' most valuable player by the local media.

His total of seven tied the mark held jointly by Maurice Richard, Jean Béliveau, Bernie Geoffrion, Guy Lafleur, and Marcel Bonin.

[33] Cammalleri began the 2010–11 season on the suspended list after earning a one-game ban for a slashing incident against Nino Niederreiter during a preseason game against the New York Islanders.

[37] He struggled throughout the first part of the season, and with the team also losing, was booed by the fans in Montreal during a 3–0 defeat against the St. Louis Blues.

[39] Two nights later, on January 12, 2012, Cammalleri was pulled from the Montreal lineup during their game against the Boston Bruins after the team completed a trade that saw him return to Calgary (along with the playing rights to goaltender Karri Rämö and a fifth-round pick in the 2012 NHL Entry Draft) in exchange for Rene Bourque, Patrick Holland, and a second-round pick in the 2013 NHL Entry Draft.

[48] On July 1, 2017, Cammalleri was promptly signed as a free agent by his original club, the Los Angeles Kings, on a one-year, bonus-laden $1 million contract.

[49] In the 2017–18 season, Cammelleri contributed with 3 goals and 7 points in 15 games before he was traded to the Edmonton Oilers in exchange for forward Jussi Jokinen on November 14, 2017.

[54] He made his debut with the senior team at the 2006 World Championships where he scored one goal and five points in eight games for the fourth place Canadians.

[55] He returned for the 2007 tournament held in Moscow, where his seven points helped Canada win the gold medal with a perfect 9–0 record.

[5] The Hockey News rates his offensive skills and intelligence on the ice as his greatest strength, but notes that he can be inconsistent away from the puck.

[64] In recognition of his service, the Canadiens named Cammalleri the 2010–11 recipient of the Jean Béliveau Trophy, a team award given annually to the player who "best exemplifies leadership qualities in the community".

[63] Cammalleri's cousin, Jonathan Erlichman, is a coach for the Tampa Bay Rays of Major League Baseball.