The Shoprite store in Ramsey closed on June 22 and is one of nine former Shoprite outlets to become Tesco stores.
It’s opening hours are 7am to 11pm Monday to Saturday, and 9am to 6pm on Sunday.
The smaller Shoprite in the town’s St Paul’s Square became a Tesco earlier this year.
Seven of the nine new Tesco stores have now opened in Castletown, Douglas, Ramsey, Port Erin, Peel and Onchan.
Tesco’s purchase of Shoprite brought to an end 51 years of trading for the island supermarket chain which was launched in 1972 by the Nicholson family.
Until the sale was announced last October, Shoprite was the biggest independently owned food chain on the Isle of Man.
Tesco has been serving customers on the Isle of Man since 2000 when it opened its flagship store in Douglas.
The first refurbished Tesco store was the Tesco Express in Castletown which opened in February.
The Ramsey store will be the last island Tesco to reopen under store director Andy Sanderson’s watch.
Mr Sanderson has been responsible for overseeing the redevelopment of the old Shoprite stores since the sale was confirmed last year.
He was brought over as store director over a year ago to manage the stores’ Tesco transition but has now accepted a role in London.
He is set to leave the Isle of Man on Saturday.
He said: ‘We're really pleased to open the Ramsey store for customers again.
‘We know it's been closed for an awfully long time, and the residents of Ramsey depend on the choice that we offer.
‘So we're really happy and all the customers have been super impressed with what we've done for them’
Speaking about his departure, Andy said: ‘I’ve taken a role in London but I’m really sad about leaving the island.
‘I’ve been here for a year now and I love it here, the residents and customers have been fantastic, really kind and welcoming, and I’m really proud of what we’ve been able to do.
‘I’ve got a replacement starting next week so there will be a seamless transition and hopefully everything will be as it has been.’
With the Ramsey store now open, Tesco has just two more Shoprite stores to convert.
The next store is on Derby Road in Peel, which is expected to open in mid to late October.
Although the official opening date has not been confirmed, Mr Sanderson shared some updates on the Peel store.
‘We're just getting some more power upgrade work done with Manx Utilities’ he said.
‘The really good news for Peel is we’ve put in an external ATM, and we know the residents of Peel have been asking for more cash access for a while.
‘So that's outside, available 24 hours a day, seven days a week.’
The final store to be rebranded under Tesco’s banner will be Winerite on Victoria Road in Douglas, which is set to open in the new year.