In almost simultanous posts on the social network, the pair, who are ringing in the New Year in Australia, tweeted pictures of a diamond engagement ring on Wozniacki's finger alongside a picture of fireworks over Sydney Harbour Bridge.
The star couple have a combined following of more than two million people on Twitter and have frequently used the social media website to have fun with their followers. Announcing the engagement, the Northern Irish golfer and current world number six told his followers : "Happy New Year everyone! I have a feeling it's going to be a great year!! My first victory of 2014 #shesaidyes!!"
Danish tennis player Wozniacki (23) -- also in her sport's top 10 -- tweeted the same pictures and a message saying: "Rory and I started 2014 with a bang!...I said YES!!!!"
The duo started dating in the summer of 2011
COMMENT RULES: Comments that are judged to be defamatory, abusive or in bad taste are not acceptable and contributors who consistently fall below certain criteria will be permanently blacklisted. The moderator will not enter into debate with individual contributors and the moderator’s decision is final. It is Belfast Telegraph policy to close comments on court cases, tribunals and active legal investigations. We may also close comments on articles which are being targeted for abuse. Problems with commenting? firstname.lastname@example.org