The 22-year-old reunites with Reds head coach Gareth Taylor, having previously worked under him at City.
Keating becomes Liverpool’s fourth summer addition and arrives with significant experience despite her young age.
“I think everyone knows Liverpool worldwide. It’s such a big club and I think the women’s team is striving for greatness,” Keating told Liverpool website.
“I think the style of football that they play, they actually try to play – which suits me and my position.
“I think they’re just going in the right direction and (it is) a project that I want to be part of.”
A product of the City academy, she made her senior debut at 17 and has represented England at youth and senior levels, earning her first Lionesses cap in October 2025.
Keating broke through during the 2021-22 season and later became City’s first-choice goalkeeper, winning the WSL Golden Glove award in 2023-24 before gaining Champions League experience.