Twitter UK has confirmed more than 3.6 million tweets were posted on Twitter about One Direction and the One Direction world premiere in London.
One Direction is the most followed UK band on Twitter with more than 14 million followers.
Twitter revealed that the hashtag #1DMoviePremiere was used more than 1.9 million times over the last 24 hours.
Niall, Louis and Liam from One Direction have spoken to ITV News ahead of the world premiere of 'One Direction: This is Us' at Leicester Square in London.
Three of the band's members spoke to ITV London's Lucrezia Millarini on the red carpet.
Even with its long history of hosting film premieres, London's West End has never seen anything quite like this. Tens of thousands of fans have been cramming themselves into every corner of Leicester Square since first thing this morning, to get a glimpse of One Direction.
Sangeeta Kandola went to meet their dedicated army of fans.
Harry Styles is "excited" about One Direction's This Is Us film premiere, the boyband's Twitter page states.