Matt Damon is mourning the death of his father.
Kent Damon died on Dec. 14 after a long battle with cancer, the actor's rep confirms to ET. He was 74.
According to The Boston Globe, Kent died of multiple myeloma, a rare blood disease, after his condition had worsened in recent months. Damon -- who revealed that his father was battling myeloma while attending a benefit for Massachusetts General Hospital in 2011 -- had pulled out of several recent public appearances due to family matters.
In October, Damon canceled his appearance at the BAFTA Britannia Awards, where he was set to receive the Stanley Kubrick Britannia Award for Excellence, and skipped Monday's premiere of his new movie, Downsizing.
Since news of his father's diagnosis, Damon has helped raise awareness and funds for cancer research and treatment. He's also attended several benefits for the Massachusetts General Hospital Cancer Center in Boston, as well as hostedd private fundraisers in Los Angeles.
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