We thought the actress lost her L plates a long time ago.
But five months after completing a European test the 27-year-old passed the UK version in style.
Earlier she had nervously edged through the back streets of West London before successfully pulling off a threepoint turn and niftily manoeuvring the three-door Corsa into a reverse park.
Then she anxiously bit her nails before the examiner delivered his Pass verdict.
Says our spy: “Sienna had been so nervous before.
She’s an accomplished driver but was desperate to be able to drive here.
“When the examiner told her she’d passed she hugged him and leapt out of the car to bear-hug her instructor.
“She is thrilled to pieces to be on the road.”