The Price Tag singer was joined on stage by Conor Maynard and James Arthur as they lit up London’s busiest shopping street.
Speaking of the event, Jessie said she was elated to have been chosen to take part.
“I’m honoured to be a part of such a big event in London’s Christmas season! What a way to celebrate the end of my tour!”
The 25-year-old went on to wow crowds with a selection of her hits, including her latest singer Thunder, but made sure she warmed up sufficiently before braving the chill – posting a picture of herself reclining on a bed before heading outside.
When she left the stage, Jessie couldn’t hide her joy at taking part in the celebration, tweeting:
“I did it! I performed on a stage really high up! I faced my fear! Thank you SO MUCH to everyone who came out and sang with me and made it less scary!”
Department Store Selfridges hosted the event after the lights on Oxford street underwent a massive £1.5 million transformation.
The display features 750,000 tiny LED bulbs and is claimed to have been inspired by falling snowflakes.