Elsa Søllesvik (born 22 April 1996), known professionally as Elsie Bay, is a Norwegian singer and songwriter.
Søllesvik grew up in Sunde before moving to Haugesund at the age of 13. She found her interest in music as a child. She now lives in Berlin, Germany.
In 2010, Søllesvik met Emilie Haaland Austrheim and formed a duo Elsa & Emilie. In 2014, the duo signed a contract with record label Sony Music and released their debut album Endless Optimism the same year. The duo was nominated for Best New Artist at the 2014 Spellemannprisen, annual Norwegian music award. "Run", a track from the album, gained popularity after being featured in the first season of the television series Skam in 2017.
In 2017, they released their sophomore album, Kill Your Darlings with singles "Au volant" and "Chains and Promises". In 2018, the duo announced their split to focus on Søllesvik's solo career.
After the split of Elsa & Emilie, Søllesvik moved to Oslo to establish herself as a songwriter for other artists. She co-wrote the track "Witch Woods", performed by Emmy, which competed at the , where it made the final. She performed the opening theme of the third part of Korean television series ', titled "Heaven Made".
On 10 January 2022, she was announced as one of the competing acts of with the song "Death of Us", co-written with Jonas Holteberg Jensen and Andreas Stone Johansson. She finished as one of the top four finalists. Apart from her own entry, she also co-wrote "Hammer of Thor", performed by Oda Gondrosen, which qualified to the final.
She returned to the competition a year later with the song "Love You in a Dream" with Andreas Stone Johansson and Tom Oehler, qualifying for the final and placing fourth. She also co-wrote Eline Thorp's entry titled "Not Meant to Be", which also qualified for the final, placing sixth.