The 19-year-old is yet to make his debut for Roberto Martinez's Barclays Premier League outfit and is still awaiting a Football League bow despite loan spells with Hartlepool, Shrewsbury and Sheffield Wednesday last season.
"I've had some good experiences but now I feel like the next step in my career is first-team football and hopefully I can get it at Accrington," said Nicholls, who is available for Saturday's trip to in-form Swindon.
"It's been very last minute but hopefully we can go down to Swindon and get the three points. Hopefully the team can push on from now and at the end of the season be in with a chance of a promotion place."
Assistant manager Leam Richardson said: "Lee is a very promising player. He's an England Under-20 international, is well thought of and we think he can improve us."
Nicholls is Paul Cook's second signing since replacing John Coleman as manager at the Crown Ground following Jamie Devitt's arrival on loan from Hull last week.