Per ESPN's Adrian Wojnarowski, Plumlee agreed to a "partially guaranteed" contract with the Clippers.
After going undrafted out of Duke last year, Plumlee signed a deal with the New York Knicks. He appeared in 21 games, averaging 1.9 points and 2.4 rebounds.
In between stints in the NBA, Plumlee also had stints with the Westchester Knicks of the then-named NBA Development League. The 25-year-old was part of Duke's NCAA championship team during the 2014-15 season.
The Clippers have been active this offseason. They made their big move by trading Chris Paul to the Houston Rockets for a package of players that included Sam Dekker, Lou Williams and Patrick Beverley.
Plumlee will get a chance to compete with Willie Reed as Los Angeles' primary backup center to DeAndre Jordan.