Actor Sean Penn (L) and actress Charlize Theron hold their Oscar statues at the 76th annual Academy Awards in Hollywood, Calif., on Feb. 29, 2004. Penn won the award for best actor for his role in the film "Mystic River," and Theron won the best actress award for her role in the film "Monster." Reuters/Mike Blake

Sean Penn and Charlize Theron are rumored to be in a relationship after being spotted together over New Year's in Hawaii.

The two were seen boarding the same flight back from Hawaii but exited the jet separately. Penn reportedly headed over to Theron’s home in Los Angeles and the duo was seen leaving the house in separate cars soon after their return from the vacation.

According to reports, Penn, 53, and Theron, 38, were spotted soaking in the sun in their bathing suits as they spent some R&R time on a beach near Penn’s home in Hawaii. And, an eye-witness told the New York Daily News that the pair was looking “very close and comfortable together.”

The two-time Academy Award winner was previously married to Madonna and Robin Wright. He ended his marriage with Robin Wright in 2010 and has two children from the marriage. Penn also dated Scarlett Johansson and singer Florence Welch.

The “Monster” actress ended her nine-year relationship with Irish actor/director Stuart Townsend in 2010. She has a two-year-old son, Jackson, who she adopted in 2012. Theron was recently linked to “Family Guy” creator Seth MacFarlane.

Penn and Theron have been good friends for years, according to reports, and the two also sparked romance rumors back in 2010 when they were spotted having a cozy dinner in Santa Monica, Calif.

But, their latest Hawaii vacation has once again fuelled speculation that the two celebrities could be dating.