Marking his first red carpet appearance since it was revealed he's set to become a dad, Louis smartened up in a black suit for the Believe In Magic Cinderella Ball held at the Natural History Museum.
'Story of My Life' singer Louis arrived at the event with his mum Johannah Deakin and he was also joined by bandmate Liam Payne.
Louis was all smiles and gave a thumbs up to photographers before going inside the venue.
Louis spoke about his baby news for the first time last week during an appearance on Good Morning America, where he said: "Obviously it's a very exciting time, I'm buzzing, thank you."
Louis, 23, is expecting a child with his friend and US-based stylist Briana Jungwirth.
It's claimed Louis and Briana met via mutual friends in May, shortly after Louis' split from long-time girlfriend Eleanor Calder.
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