As the college basketball's Player of the Year in 1995-96, Marcus led Massachusetts to its finest season and its first-ever NCAA Final Four berth. Camby was a consensus National Player of the Year selection by the Associated Press, U.S. Basketball Writers Association, CBS/Chevrolet, Basketball Weekly and The Sporting News. He won the Naismith and Wooden Awards as Player of the Year and was selected First Team All-America by AP, UPI, USBWA and Basketball Weekly. He led UMass to a 35-2 record in 1995-96 and the school's first-ever berth in the Final Four, averaging 20.5 points, 8.2 rebounds and 3.9 blocks. He was named MVP of the NCAA East Regional and set an NCAA Tournament career record with 43 blocks in 11 games. He posted a UMass record 336 blocks in 92 career games and became only the fourth college player ever to surpass 300 career blocks.

He was selected by the Toronto Raptors in the first round (second pick overall) of the 1996 NBA Draft. He was traded by the Raptors to the New York Knicks for Charles Oakley, then traded by the New York Knicks along with Mark Jackson to the Denver Nuggets. 

Marcus' 2005-06 NBA season was one of his most productive season's ever which made him a MVP candidate for the entire NBA.

Camby played in 23 games for the Portland Trail Blazers in the 2009-2010 season where he helped the team secure a playoff berth as the Western Conference's six seed. On April 20, 2010, he signed a two year contract extension to stay with the Portland Trail Blazers.

Camby was traded in 2012 to the New York Knicks.