The facade of the building has been turned multi coloured as part of the Lumiere London displays.
The installation, The Light of the Spirit, has been designed by the French artist, Patrice Warrener.
He's lit more than 60 buildings around the world, and is known for his intricate, vibrant illuminations.
It's the first time that Westminster Abbey, a designated World Heritage Site and one of the UK's leading visitor attractions, has been lit in this way.
Light installations by 30 leading artists have appeared across the capital in King's Cross, Mayfair, Piccadilly and Westminster.
The Lumiere festival was started in Durham in 2009 where the festival takes place every two years.
It's free to visitors and runs until Sunday night.
