"Mr. Blue Sky" is a song by the British rock band Electric Light Orchestra (ELO), released in 1977 on their album Out of the Blue. The song is known for its upbeat melody and orchestral arrangement, featuring strings and harmonies that create a joyful atmosphere. It celebrates the arrival of sunny weather and the positive feelings that come with it. The song has gained popularity over the years, often used in movies, commercials, and television shows. Its catchy chorus and vibrant sound have made it a favorite among fans, contributing to its status as one of ELO's signature tracks.