Manchester City were reported to be preparing a £60m move for Van Dijk, but the Reds have moved to beat the Premier League leaders to his signature.
It was revealed today that Southampton have agreed a fee with Liverpool for the Dutch centre-back.
A statement on the club's website read, "Liverpool Football Club can confirm they have reached an agreement with Southampton for the transfer of Virgil van Dijk".
In terms of van Dijk's own payment, it is expected that he will be on anything from £180,000 a week upward.
Getty Virgil van Dijk finally gets his move to Anfield next month
Should the deal go through, Van Dijk will become the joint second most expensive player in Premier League history - equalling the cost of Manchester United's Romelu Lukau, and falling short behind Paul Pogba's £90m transfer fee from Juventus to United in the summer of 2016.
The 26-year-old has endured a hard season at St Mary's Stadium but nonetheless insists he will "always be indebted" to his old club after spending more than two years on England's south coast.
Van Dijk previously handed in a transfer request in a bid to force a move to Liverpool, leading to then-Southampton manager Claude Puel exiling the defender from first-team action.
Speculation had been rife regarding van Dijk's future after he was absent from the matchday squad for Southampton's past two games.
Many Saints fans will be disappointed to let yet another top player slip through their fingers to Liverpool - following the departures of Sadio Mane, Dejan Lovren, Nathaniel Clyne, Adam Lallana and the now-retired Rickie Lambert.