Aalto auditioned for the thirteenth UK series of The X Factor in 2016 in front of attending judges Simon Cowell, Louis Walsh and Nicole Scherzinger, singing a cover of Sia's "Chandelier", which earned her three yeses from the judges. At bootcamp, she performed "On the Radio" by Donna Summer and was sent through as part of the over-25s category, mentored by Sharon Osbourne, who was not present at her audition. At the six-chair challenge, she performed "I See Fire" by Ed Sheeran and was sent home by Osbourne who stated a lack of connection. However, after the crowd chanted to bring her back, Aalto was given a second chance and performed "Je suis malade" by Serge Lama, which caused the crowd to turn on her, while Scherzinger criticized her song choice, stating "we ain't in France". Osbourne then asked Aalto to leave.
In a press-conference in December 2016, Aalto revealed that she works with the joint effort of ROAR Global and Global career management companies, and that she has signed a five-album recording deal with Sony Music UK and Sony Music Finland. In October 2017, Aalto announced she had left Sony Music for Warner Music Group. In a statement, she said: "I was honoured I was signed to Sony. But later I felt like they weren't the right team. When I met the people at Warner they were very excited about my style and making me into this big theatrical artist." On 7 November 2017, it was announced that Aalto would represent Finland in the Eurovision Song Contest 2018 in Lisbon, Portugal. The three bidding entries were released by Yle and Saara Aalto, along with an accompanying music video. Aalto was a judge on the second series of the Finnish version of The X Factor, mentoring the girls. Aalto could not attend the finale night of The X Factor Finland due to her commitments with Eurovision, so Terry represented her instead, but her category's last girl, Tika Liljegren, was crowned the winner, making Aalto the winning mentor. Aalto announced in March 2018 via social media that her first album under Warner Music Group, Wild Wild Wonderland, would be released on 27 April 2018.
