The guys were pictured arriving at Cirque Le Soir nightclub in London on Monday evening (2 November), alongside stars including Caroline Flack and Fleur East.
They went for rather different dress: Liam was casual in a checked shirt and trousers, while Niall was uber dapper in a fitted black suit.
One Direction played the final gig on their 'On The Road Tour' in Sheffield at the weekend, marking the end of a mammoth tour across the world that took in 20 countries.
For 1D fans, it was also a sad occasion, as it's believed to be the band's final concert performance before they go on hiatus in March 2016 for a well-deserved break.
The band – which also features Harry Styles and Louis Tomlinson – have insisted they are not splitting and are simply taking a breather after five years of non-stop work since they found fame on X Factor.
Before the hiatus starts, however, they will release new album, Made In The AM, and promote the record, including performances at the BBC Music Awards and American Music Awards.