John Stamos is to become a father for the first time.

The 54-year-old actor is delighted his fiancee Caitlin McHugh is pregnant and has vowed to be a ''fun dad'' to their baby, following years of practice on his hit TV show 'Fuller House' and its predecessor 'Full House'.

He said: ''I'll be a fun dad. I've been practicing for a long time. I've done every schtick you can do with a baby on TV ... all the bits and jokes and diaper gags. I'll probably just do all that stuff.''

John has ''always wanted'' children but wasn't sure it was going to happen for him.

He told People magazine: ''People would say, 'You should have a child.' I was like, 'That ship has sailed.' ''

The brunette beauty will never forget breaking the news to John that she was pregnant.

She recalled: ''The look on John's face when I told him we were pregnant was priceless.

''It was the look of a man who has wanted a family of his own but wasn't sure it was going to happen for him. Now it is!''

And Caitlin thinks her partner will be an ''amazing'' father.

She gushed: ''[He has] the biggest, most loving and generous heart of anyone I know.

''I greatly admire his originality, creativity, ambition, work ethic and humour -- all qualities I'm sure he'll pass down to his child.

''He's always been wonderful with kids, and I'm sure he will be an amazing father.''

John proposed to Caitlin in October after over a year of dating, and though he'd been keen to pop the question, it was the pregnancy news that spurred him on to do so.

He said: ''The [pregnancy] happened. Then I said, I better have a ring on her finger because it's the right thing to do, and I wanted to marry her anyway.

''So I called her parents to ask, and it was like, 'You better!'''