“Gravity” star Sandra Bullock didn’t attend the BAFTAs show in London on Sunday night because her son, Louis, wasn’t feeling well, sources said.

Bullock was expected to walk the red carpet along with Leonardo DiCaprio, Brad Pitt and Angelina Jolie, and Prince William and Catherine.

Bullock’s film was the big winner of the night — along with “12 Years a Slave” — including a best-director honor for Alfonso Cuarón.

The director celebrated at a Warner Bros. bash thrown by studio exec Sue Kroll at Little House Mayfair.

Harvey Weinstein hosted a party at the Rosewood Hotel where “20 Feet From Stardom” singer Claudia Lennear mingled with Judi Dench.

Spotted at Berners Tavern for “12 Years a Slave” were Pitt, Michael Fassbender and Chiwetel Ejiofor.