|IS LALLANA WHAT LIVERPOOL NEED?
|DOSSIER: The England midfielder could fulfill a crucial role at Anfield next season|
"I've been granted my wish to play at such a fantastic football club, in Champions League football and competing for Premier League titles," the 26-year-old said.
"I'm so excited for the next chapter of my career, coming to a special club like Liverpool. Last season, deep down, I was thinking: hopefully one day I'll be able to play in that team. That dream is reality now."
Lallana, who appeared in all three of England's fixtures at the World Cup, made 38 Premier League appearances last season, scoring nine goals and laying on eight assists.
"We're delighted to have secured one of the Premier League's top talents," said Liverpool manager Brendan Rodgers. "I'm excited about working with Adam and helping him progress even further."