Having amassed 1.078 million streams, the BBC Studios-produced event has surpassed the opening ceremony of the London Olympic Games 2012, which previous held the record.
Broadcasters and services in more than 50 territories watched the concert, which singer Ariana Grande put together after the terrorist attack at her concert in Manchester last month.
Acts such as Justin Bieber, Katy Perry, Take That, Black Eyed Peas, Miley Cyrus and Liam Gallagher appeared alongside Grande at One Love, which was filmed at the Emirates Old Trafford Cricket Ground on Sunday (June 4).
In the UK, the terrestrial broadcast on BBC One peaked with an audience of 14.5 million and an average of 10.8 million. This makes it the most watched TV show of the year so far.