It is in the former Six Bells Pub on North Street in the town centre, which closed down in April last year.
The store has been unused since its closure and Caprinos Havant owners, Tamour and Sadaf Malik are hoping to bring a new lease of life into an historic building.
Tamour said: ‘From what we know, the Six Bells was a much-loved pub in the town and we’re glad that we’re able to open up a business in such a famous spot.
‘I think the residents will also be glad to see that the unused venue is being used for a new business, rather than being turned into residential property, as it proves that the high street is regenerating, and business is beginning to see a boom again after such a tough two years.’
The new venue is offering a vast range of pizzas, from margarita to Mexican hot, healthy salads, as well as side dishes such as chicken wings, stuffed mushrooms and potato wedges.
There are dishes for those with a sweet tooth too, with a full dessert menu, including vegan chocolate brownies.
Halal, vegetarian and vegan options are also available on all menus.
To mark the grand opening, the restaurant is offering 50 per cent off pizzas from 6pm onwards on April 13 until April 14 and 25 per cent off from April 15 until April 17.
Tamour added: ‘We want to kick off with a bang, so why not offer deals that people can’t refuse?’
The Havant restaurant will be the first Caprinos – which is a franchise and has venues across the country – in the Portsmouth area, with the other nearest one being in Southampton.
It is open from 11am until 11pm and orders can be made via Deliveroo or at caprinospizza.co.uk.