The 71 year olds appeared to be enjoying each other's company at Pierluigi in Rome on Thursday (26Aug21).
Anna and her husband of 16 years, Shelby Bryan, split last year (20) and sources claim she and Nighy have been getting closer.
In photos obtained by the Daily Mail, Bill appeared to buy roses for his date before joining her at the restaurant.
Anna Wintour and Shelby Bryan never talked about their relationship in interviews.
She once explained why she never bothered to clear up any rumors about her private life, "There are certain things that no one wants to read about in the tabloid press...You know that your friends and your family have one vision, and if the outside world has another, then that's just something that you just don't focus on."
Similarly, Bryan said in a separate occasion, "There's an old-fashioned view that your personal life should be kept private, and that's my view."
Before tying the knot with Bryan, the fashion magazine editor was married to psychiatrist David Shaffer. They share two children together.
Last month, her daughter Bee Shaffer showed baby bump during a vacation with husband Francesco Carrozzini.
The child will be the couple's first, and Anna's third grandchild - her son, Charles Shaffer, is dad to daughters Ella and Caroline.