The British director - who has been linked to several women including Jemima Khan and Elle Macpherson since splitting from wife Madonna last November - dined at the Marmalade cafe in Los Angeles before taking a stroll along the beach with the unnamed woman.
The RocknRolla filmmaker appeared content and relaxed as he walked injeans, T-shirt and a knit vest alongside his stunning companion, who had chosen a white maxi dress, cardigan and high-heeled shoes for their date.
Guy's date came on the same day Madonna was accompanied by her 22-year-old boyfriend Jesus Luz and sons Rocco, seven and David, three, to the Veuve Clicquot Manhattan Polo Classic in New York.
Meanwhile, a nude portrait of Guy and Madonna has failed to sell.
The 2005 work, entitled Madonna and Guy, was created by acclaimed Scottishartist Peter Howson - who has painted several pictures of the 4 Minutes singer in various states of undress - and was put up for sale by a private collector at auction in Glasgow but it failed to meet the £15,000 reserve price.
Brian Clements, director at McTear's Auctioneers, said: "The auction was very successful, however, surprisingly, Peter Howson's controversial piece Madonna and Guy did not sell on the day.
"The painting is still for sale and we would be delighted to hear fromanyone who is interested in this much talked about piece of Scottish art history."
- Bang! Showbiz