Theodor Jan Haraldsson (born 17 July 2005), known mononymously as Theo (formerly Theoz) is a Swedish social media personality, singer and actor. He started his career by posting videos to Musical.ly in 2016 with the name Theoz. In 2020, he had a leading role in the movie Rymdresan opposite Robert Gustafsson. In 2021, he performed his music at Lotta på Liseberg, which is broadcast on TV4. Theoz participated in Melodifestivalen 2022 with the song "Som du vill", which finished 7th, and in Melodifestivalen 2023 with "Mer av dig", which finished 5th. He participated as a celebrity dancer in Let's Dance 2025 broadcast on TV4.