updated 05/28/2012 AT 7:30 PM ET
•originally published 05/28/2012 AT 11:30 AM ET
Keira Knightley was flashing more than her megawatt smile Sunday in London – she also showed off her engagement ring from James Righton.
The British actress, 27, who is newly engaged to the Klaxons keyboard player, 28, was sporting what appeared to be a circular diamond on a thin gold band as she strolled around town with her fiancé – the two of them kissing much of the way.
The pair were dressed for early summer – England has been hit by a heat wave in recent days – with Knightley in a denim skirt and white T-shirt and Righton in light pants, a white T-shirt and a striped long-sleeve shirt.