The 19-year-old joins Scott Rogers’ side having come through the ranks at Crystal Palace Ladies before moving to Millwall Lionesses in 2015.
Following two years with Millwall, she then moved to Watford Ladies in 2017, finishing as the Hornets' joint-top scorer in the Spring Series with three goals in nine appearances.
On moving to Merseyside, Babajide said: “I am absolutely delighted to be joining a club as big as Liverpool Ladies and cannot wait to get started. This is a huge opportunity for me to make the step up to FA WSL1 and I am really excited to meet my new teammates.
“I have really enjoyed my time at Watford Ladies but this is a massive opportunity for me to join a huge club who have established international players throughout the squad. I am really excited about the move and can’t wait to pull on the red shirt for the first time.”
Ladies manager Rogers said: “This is a really exciting signing for the club. Rinsola is a quick, direct player who has a lot of ability and I am sure she will prove what a quality player she is once she settles in at the club.
“I know that a few other clubs in FA WSL1 tried to sign Rinsola so we are delighted that she has chosen to join Liverpool Ladies. Rinsola is also able to operate right across the forward line so this signing gives us more options as we look to strengthen the attacking area of the team.”