Casspi was part of a five-player trade between the Pelicans and the Kings with home he enjoyed a successful spell.
The Israeli NBA star moves to the Pelicans with Kings star and close friend DeMarcus Cousins, while three Pelicans players join the Kings.
Casspi, 28, will hope to reignite his stalled NBA career. He has been sidelined by a calf injury since January 13 and was only averaging 19 minutes and 5.9 points per game this season. This was disappointing as last season was Casspi's best since joining the NBA in 2009 with an average of 11.8 points and a frequent place in the starting five.
The 6ft 9" forward has signed a two-year $6 million contract which ends this season, giving him two months to persuade the Pelicans to offer an extended deal.
He spent five seasons with the Kings and also had spells at the Cleveland Cavaliers and Houston Rockets as well as the Pelicans who waived his services after a previous trade. Casspi will be hoping history doesn't repeat itself.
He said: "It was not an easy decision to leave. I've always felt at home in Sacramento and I'll carry on supporting the team from afar.
“The team, the city and the fans will always be there in my heart."
General manager Dell Demps said: "We're thrilled to welcome Omri Casspi to the New Orleans Pelicans family.
“This is an exciting time for Pelicans fans as we continue our quest for long-term success.
“I know our fans are equally excited to welcome DeMarcus and Omri to our great city."