The 20 year-old, who is now a full Northern Ireland international, has agreed terms on a deal until the summer of 2027.
McCausland has made nine appearances for the Rangers first-team thus far, with six of them coming under manager Philippe Clement since he joined the club in October.
A Rangers supporter from birth, McCausland has quickly established himself as a favourite among the Light Blues’ faithful with his performances under the new boss.
Speaking after agreeing his new contract, McCausland said: “I’m really pleased to have agreed this new deal with the club.
“I’m extremely grateful to the new manager for giving me an opportunity in recent weeks, and I want to repay him and everyone at the club with my performances on the pitch in the years to come.”
Manager, Philippe Clement, added: “I am really pleased with the progress Ross has made in recent weeks, and he is deserving of this new contract.
“Ross is a talented young player, and I think it is an important step from the club to move to secure his future here.”