The experienced central defender joined the Belles from Lincoln City Ladies in 2011 and played a crucial role last year as the Belles won the WSL 2 title.
Little, 33, will be reunited with Neil Redfearn ahead of his first season in charge of the Reds.
On signing for Liverpool Ladies, Little said: "This is a fantastic move for me as well as the chance to continue to work alongside Neil [Redfearn].
"Liverpool Ladies is a big club with real ambitions to compete at the top end of the table so I am really optimistic ahead of the new season.