The move comes on the back of a busy season for Henderson, one that hasn't ended just yet, with the 20-year-old currently preparing for the Under-21 European Championships in Denmark.
Speaking for the first time since his move to the Merseyside, Henderson tells liverpoolfc.tv about how excited he is about pulling on a Liverpool jersey.
"I'm over the moon, overjoyed to be here and I'm really looking forward to it. I cannot wait to play at Anfield in front of the Liverpool fans and everything. I'm just excited and I want to get going."
But many of you will be asking, who is Jordan Henderson and why is he such a significant signing?
To answer your questions, here's a guide to the Reds' £20 million midfielder, Jordan Henderson.
1. Born in Sunderland on 17 June 1990.
2. Just two players completed more key passes than Henderson in the 2010-11 season. The 20-year-old completed 78 and was only beaten by Kevin Davies (86) and Florent Malouda (113).
3. Played his first league game for Sunderland as a halftime substitute on 1 November 2008 and then made his first Sunderland start and home début against Blackburn.
4. Has scored six goals in his entire career
5. Has so far represented England nine times at three different levels.
Henderson has been at Sunderland since the age of seven and helped his U18 side to back-to-back premierships. In 2008, manager Roy Keane brought Henderson on during a 5-0 drubbing to the hands of Chelsea.
A short time later, he arrived at Coventry City on loan but a metatarsal injury meant that his time at Coventry was unsuccessful, and went on to only make 13 appearances.
After he arrived back at the Stadium of Light, Henderson made 38 appearances in the 2009-2010 season, an achievement that landed him the title of Sunderland's Young Player of the Year—a title that he went on to retain last season.
In November 2010, Henderson was picked in Fabio Capello's squad for England's clash against France thanks to an array of impressive performances that continued right through to the final day of the 2010-2011 season.
To top it all off, the 20-year-old was listed on the official FIFA website as one of 13 young players to watch in 2011, being hailed as "Composed, athletic and powerful."
1. Superb energy and athleticism.
2. Good touch.
3. Impressive vision—creates a lot of chances.
4. Young and versatile.
1. Has scored very few goals.
2. Is said to be not physical enough to play in the centre of midfield.
For Sunderland, Henderson has played in a variety of positions but has usually been deployed in the centre of midfield or on the wing. For a few reasons, I think Henderson will play on the wing in the Liverpool lineup.
Firstly, Henderson has been criticized for not being physical enough to play in a centre midfield role and often has a lesser effect on the game in the middle of the park than when he plays on the flank. On the wing, the 20-year-old can put his brilliant athleticism and superb crossing ability to use to have a bigger influence on the game.
Secondly, Liverpool have a huge number of central midfielders to choose from (Gerrard, Lucas, Poulsen, Spearing, Shelvey and Meireles) and a lot of those options are fine young prospects. There is quite simply no need to add Henderson to that group of players, for the quality that is there already is good enough.