The filmmaker is bouncing back after his divorce from Madonna, and is now dating the Brazilian beauty, according to the Sunday Mirror.
The 26-year-old actress, who starred in Iron Man, was introduced to the director by her friend, Robert Downey Jr. The two men worked together on the film Sherlock Holmes.
"She looked very at ease in his company," said a witness about Gandara, who was hanging out with Ritchie at the Punch Bowl in London.
Since his split from Madonna, several women have been linked to the director, including Elle Macpherson and actress Kelly Reilly.