Hollywood's top 10 art collectors

For these Hollywood superstars, art collecting is serious business.

Even after selling two of his most valuable works, entertainment industry mogul David Geffen has amassed an art collection worth an estimated $2.3 billion—or nearly a third of his total net worth of $7 billion, according to a new report from Wealth-X.

Read MoreBeware an art market bubble, Roubini warns

And that's after Geffen's notable sales of Jackson Pollock's "Number 5" and Willem de Kooning's "Woman III" for a combined $277 million in 2006.

But Geffen isn't alone in his interest in the art market. According to the report, the combined value of the works owned by Hollywood's top 10 collectors totals $3.9 billion, or 16 percent of their collective net worth.

No doubt the soaring value of art has helped to boost these numbers. Talk of an art bubble has persisted as worldwide sales of art rose to an all-time high of $53.7 billion last year, according to the annual TEFAF Art Market Report.

Read More$1.32M card sale=bargain?

But owning art isn't just about the investment. There presumably is the enjoyment of the artwork itself as well as the prestige it brings.

"Star Wars" creator George Lucas' vast collection includes works from Norman Rockwell and Alberto Vargas, among others. He'll be sharing parts of his collection with the public once his $300 million museum in Chicago opens, possibly by 2018.

Read MoreArt, real estate are the new gold: BlackRock CEO

Wealth-X estimates Lucas' collection to be worth $600 milllion, which places him second to Geffen on the list.

The entire top 10 ranking is below.