His romance with his personal assistant Anne-Marie Corbett blossomed as she supported the star through recent problems.
The separated mum, 42, also stood by Ant — who is divorcing his wife — during his drink-driving crash shame.
A source said: “Anne-Marie’s put him back together again. Everyone’s thrilled he’s found someone to love.”
She was pictured walking Ant’s dog with him in The Sun on Sunday in April after he left rehab.
One told The Sun on Sunday: “He’s had a tough time of it, but Anne-Marie has put a smile back on his face again. She has been his rock.
“They have been living in each other’s pockets, day in, day out.
“Knowing someone is there for him has brought him back from the brink — she’s put him back together again.
“It’s very early days, but everyone is hoping he can put the worst year of his life behind him and find happiness again. Both of them deserve it.”
In a show of support and commitment, Anne-Marie was with Ant when he was taken to a police station after his arrest for drink-driving in March — and again when he appeared in court.
Anne-Marie has been on hand any time he feels he needs help to overcome any urges to drink.
She separated from her husband Scott last October. They have two children.
Sources stressed Ant was not linked in any way to her marriage break-up.
In January this year, Ant announced he was divorcing his wife of 11 years, Lisa Armstrong.
They have been having legal discussions but there have been no divorce hearings in court so far.
Ant’s new relationship echoes that of his devoted TV partner Declan Donnelly.
Dec, 42, is expecting his first child with wife Ali Astall in September.
They had also worked together. Ali was Dec and Ant’s manager.
Anne-Marie has been employed by the same London-based management company as Ali for ten years but only recently began working closely with Ant.
The source added: “She’s been at his side for this whole ordeal, often when everyone else has gone away.
“His lowest moment was when the drink-drive case judge said he had lost his good character, but Anne-Marie stayed supporting him.
“She has worked with him for a while as his PA and things have always been strictly professional.
“But recently something changed and they started becoming more than just friends.
“Both of them are single so they decided to try and see whether something could happen.
“They haven’t actually been on any official dates but they’ve been seen together, with Ant always beaming from ear to ear. They don’t live together, but have been living out of each other’s pockets.
“Since he has come out of rehab, Ant can’t really go out socialising, to restaurants or anything like that.
“It means he has spent an awful lot of time with her and has realised she’s the one for him.”
The pair have been seen together as early as March this year when she sent him off to work with a packed lunch. They were spotted again this month enjoying a shopping trip at Harrods, with Ant looking healthy and happy.