The two were spotted sharing a tender kiss, reported Daily Mail online.
Boyle, 55, who put up a stunning opening ceremony for the 2012 London Olympics just last week, was spotted relaxed as he strolled hand in hand in the sunshine in Brighton with 33-year-old Dawson.
The couple met after Boyle hired the actress for his latest film "Trance", a crime thriller.
Dawson, who dated "Sex and the City" actor Jason Lewis for two years before they split in 2006, even had a plum spot at the opening ceremony.
Last year, she broke up with French DJ Mathieu Schreyer.
Meanwhile, Boyle has three children, Gabriel, Caitlin and Grace, with his ex-girlfriend Gail Stevens. The couple split in 2002 after 20 years together.