Van Dijk was sold by Celtic after their defeat by Malmo in Champions League qualifying last week |
The defender had a medical on Monday and has now joined the south coast club for a fee of £11.5million.
Saints boss Ronald Koeman is a huge admirer of Van Dijk and was desperate to add the 24-year-old to his squad.
'I'm delighted. It was a very easy decision to join this club,' Van Dijk told saintsfc.co.uk.
'This is a very ambitious club, who have been doing very well in the last couple of years. It's a great place to be and it's the right step for me.
'For me now to get the opportunity to play in the Premier League is unbelievable and I will enjoy it.
CONFIRMED: #SaintsFC completes the #deadlineday signing of @VirgilvDijk from @celticfc on a five-year contract.
https://t.co/2Oj5TEzyin
— Southampton FC (@SouthamptonFC) September 1, 2015
— Southampton FC (@SouthamptonFC) September 1, 2015
'I know it's an ambitious club – they have been through a lot throughout the years. They are trying to play football and that's something that really attracted me.'I'm so excited. I hope to settle in really quick, get everything around football sorted, start playing and enjoying it because the most important thing in football is to have fun and enjoy every day.'
The Dutchman becomes Koeman's ninth summer signing following the arrivals of Juanmi, Cedric Soares, Cuco Martina, Jordy Clasie, Oriol Romeu and Harry Lewis and the loan moves for Maarten Stekelenburg and Steven Caulker.
A spokesperson for Celtic said: 'Celtic did absolutely everything we could to keep Virgil at the club, including an offer of a new extended contract on a number of occasions.
Van Dijk becomes Southampton's ninth summer signing as manager Ronald Koeman reshapes his squad |
'Virgil has served Celtic very well for the past two seasons, we thank him for his contribution to the club and we wish him all the best for the future at Southampton.'
Source: Bloom Sports Desk