The low-key pair practically went undercover at the event, which was presented by Levi's Brand and RE/DONE Levi's with Tequila Don Julio. Rihanna sported glittery over-sized sunglasses, while DiCaprio covered up in a University of Michigan baseball hat, dark sunglasses and a blue patterned bandana.
The 41-year-old Oscar winner slipped into the party unannounced but clearly enjoyed himself, even singing along to every word of TLC's 1999 hit, "No Scrubs." Rihanna, 28, danced with two girlfriends at a table a few down from DiCaprio and his pals.
After the two met up, the "Kiss It Better" singer was seen smiling as DiCaprio whispered in her ear.
The A-list bash was also attended by a number of other Coachella-loving celebrities, including Aaron Paul and his wife, Lauren -- who adorably met at the festival a few years ago -- Karlie Kloss, Nina Dobrev, Derek Hough, Kellan Lutz, Josh Hutcherson and Kyle Richards.
Earlier in the evening, Rihanna was spotted with Courtney Love during Guns N' Roses highly anticipated set, while DiCaprio was spotted at a few various spots throughout the first two days of the festival.
Rumors first started that the pair might be casually seeing each other in January 2015, and they were spotted flirting at a series of birthday parties over the following months, as well as reportedly partying together in New York City last May. They were supposedly seen getting close at a nightclub in Paris this past January.
The pop star is actually in the middle of her Anti World Tour, which she'll return to with a show in Winnipeg, Canada, on Monday. She was just seen getting hot and heavy with her friend and rumored love interest, Drake, at her concert in his hometown of Toronto last week.
Get it, girl! After all, she did admit to Ellen DeGeneres in February that she barely has time for "even a text," let alone finding "the time to entertain a steady relationship or anything serious." See more from the interview in the video below.