James used his 27th birthday/New Year's Eve party to propose to Brinson, his longtime girlfriend and mother of his two sons.
James got down on one knee and slipped a large diamond ring on Brinson's finger, reports said.
"It was real cool," James was quoted as saying. "It was an opportunity for me with my personal life, so it was good. My girl, she's very excited."
James' engagement means two members of the Heat's Big Three are off the market. Forward Chris Bosh married Adrienne Williams in June. Dwyane Wade was the first to get married, but he filed for divorce from high school sweetheart Siohvaugh Funches in 2007 and has reportedly been dating actress Gabrielle Union.