In a private ceremony last week, the enigmatic and volatile star renounced the bachelor's life in a union of two famous literary names.
He, the son of the late Poet Laureate Sir Cecil Day-Lewis, wed Rebecca Miller, the film-maker/actress daughter of Arthur Miller, arguably the greatest living American playwright.
The occasion was surrounded in high secrecy. The 39-year-old actor notoriously loathes any intrusion into his privacy, although as one of Britain's great acting successes with an eye for some of the world's most beautiful women, he has always failed to quell the public probing.
While refusing to give details, Day-Lewis's sister Tamasin Day-Lewis, a documentary and film-maker three years his senior, yesterday confirmed the wedding had taken place.
The bride's guest list was headed by her father and mother, Miller's third wife, the photographer Inge Morath, to whom has has been married for 34 years.
"It was completely perfect," Ms Day-Lewis said yesterday. "It was a family occasion, terribly small, with only the closest people there. Everyone was fantastically happy and he's fantastically happy."
The good thing about the wedding, which, it is understood, took place in the United States, was that the press had only discovered it afterwards, Ms Day-Lewis said.
"What was an incredibly private occasion managed not to be discovered by the press. He did it how he wanted to."
Daniel Day-Lewis's personal and professional life has been a source of much conjecture ever since he came to fame portraying a gay punk in My Beautiful Laundrette (1985).
The highs have seen him feted in Hollywood, where he won an Oscar in 1990 for best actor for playing Christy Brown in My Left Foot. The lows included fleeing the stage of the National Theatre mid-performance in 1989 when he cited nervous exhaustion for his inability to continue playing Hamlet.
He is renowned for throwing himself completely into any role, becoming almost indistinguishable even off-duty from the character he is portraying. One of his rare comments on marriage was about his acting, not his love life. "I've always allowed the work to dictate to me, by necessity, the circumstances of my life. It's a marriage," he said.
Yet his romantic liaisons have always won him as many column inches of publicity as his performances.
He has romanced the actresses Julia Roberts and Winona Ryder, coincidentally now his co-star in a film of Arthur Miller's The Crucible. Other gossip has linked him with the singer Sinead O'Connor and the actresses Greta Scacchi and Juliette Binoche. For six years, he had a fiery relationship with the beautiful French actress Isabelle Adjani to whom he wrote wax- sealed letters. Day-Lewis is reported to have ended the love affair by fax shortly before she gave birth to his child 18 months ago. But his side of the incident, which generated a great many column inches of press comment, was never publicly aired.
It is understood that he met Rebecca Miller while working on the screen version of The Crucible, which is due to open in the United States this week. She is an actress and movie-maker noted for the prize- winning film, Angela, about a girl with a manic-depressive mother.
However, Day-Lewis had worked hard to keep the relationship under wraps and exploded in irritation when questioned about it at a press conference for The Crucible only days before the wedding ceremony. Asked whom he had met first, Arthur or Rebecca, he said: "It is a good thing you asked me this at the end or I would have left immediately."
Daniel Day-Lewis and his sister were the children of their father's second marriage, to the actress Jill Balcon. They adored him although they were only 18 and 15 respectively when he died.
He is said to lament the fact he never knew his father well and Tamasin has spoken of having much to live up to. "It is awesome to feel you are carrying on the family name."
Perhaps Rebecca Miller knows how the Day-Lewises feel.