Louis was joined at the nuptials of Johannah Poulston and her long-term partner Daniel Deakin in Manchester, North West England by his bandmates Harry Styles, Liam Payne and Niall Horan, though Zayn Malik did not appear to be in attendance.
Louis - who donned a blue suit - was also joined by his girlfriend Eleanor Calder, who was one of Johannah's bridesmaids.
Harry kept up his rock star persona with an all black ensemble and left his shirt unbuttoned, exposing his chest tattoos. He completed the look with a wide brimmed black hat and a patterned black scarf and seemed to spend much of the day with the group's hairdresser, Lou Teasdale. The silver haired stylist posted several photos from the day on Instagram, including one with the caption: ''It's a lovely daaaaaaay''
Liam arrived with his girlfriend Sophia Smith, who looked gorgeous in a tight fitting black dress. The 20-year-old pop star appeared to co-ordinate with his date as he also wore a black suit with matching waistcoat.
Also looking dapper was Niall, who wore a striped shirt and green tie for the happy occasion.
He was later spotted enjoying a game of croquet with Liam, as they relaxed after the ceremony.
He also slapped a jet-lagged Taylor Hawkins.
The acclaimed performer had just cancelled touring due to a battle with cancer.