Lallana, 26, completed his move to Anfield from Southampton on Tuesday in a deal believed to be worth £25 million, following former team-mate Rickie Lambert to Merseyside.
Liverpool came close to ending a 24-year wait for a 19th English top-flight crown last season, but missed out to Manchester City on the final day of the campaign.
Brendan Rodgers' men thrilled the league with their attacking brand of football, scoring 101 goals in 38 games, a mark only bettered by champions City.
And Lallana has expressed his delight at joining a team he enjoyed watching last term.
"Liverpool have got so much history and after the season they had last season, I can't wait to get started and carry on and build on that," Lallana told Liverpool's official website.
"Watching the run-in towards the end of last season was unbelievable, not just for myself but everyone involved in football.
"It got the hairs on the back of my neck standing up just watching them, and the style of football they were playing.
"Deep down, I was thinking to myself: hopefully one day I'll be able to play in that team. That dream has become a reality now, so I can't wait for that to get started."
