Pitt, who co-starred with Hill in Moneyball, was seen mingling with his partner Jolie and other guests at Hollywood's La Descarga as DJ Bobby French provided the entertainment.
"They danced a little bit… Angelina had a glass of wine in her hand," an eyewitness told Us Weekly.
New Girl star Zooey Deschanel was also at the party and apparently spent the evening "tearing up the dancefloor".
Hill was recently nominated for both Screen Actors Guild and Golden Globe awards for his portrayal of a baseball strategist in Moneyball.
The star has described the award nods as "thrilling" and "surreal".
Hill next co-stars with Ben Stiller in the sci-fi comedy Neighborhood Watch, opening on July 27 in the US and August 22 in the UK.
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Watch Brad Pitt and Jonah Hill in the Moneyball trailer below: