Video Assistant Referees (VAR) technology will be used in the knockout stages of this season's Champions League and Europa League competitions.
European football's governing body confirmed the move following the meeting of its executive committee in Dublin.
VAR will also be used at next summer's Nations League finals.
The Champions League last 16 gets under way in February next year.
UEFA president Aleksander Ceferin said: "We are ready to use VAR earlier than initially planned and we are convinced that it will be beneficial for our competitions as it will provide valuable help to match officials and will allow to reduce incorrect decisions."
CONFIRMED: Video Assistant Referees (VAR) will be used in the @ChampionsLeague from the Round of 16 in Feb 2019 following successful technological testing and the training of referees over the last few months 📺#UEFAExCo pic.twitter.com/r3cOzjahUo— UEFA (@UEFA) December 3, 2018
UEFA referees chief Roberto Rosetti said UEFA would use the same protocol as other associations but would seek in its guidelines to define the line of intervention clearly.
"We are speaking about consistency, uniformity. The communication is another key part of the project. We have to be very clear and communicate in the best way to the fans, players and coaches," Rosetti said.