'Halo'是'I am Sasha Fierce'专辑的第四波单曲。这首歌是由Ryan Tedder 和 Evan Bogart共同制作和创作。这首原本是Ryan Tedder和Evan Bogart推荐给Lewis唱的，只不过，Lewis并没有时间录音。由于Ryan Tedder想要把这首歌快点推出，所以就转让给Beyonce。
"Halo" is a song recorded by American R&B singer Beyoncé Knowles. The song was composed by Ryan Tedder, Evan Bogart and Knowles for her third studio album I Am... Sasha Fierce (2008). It was released on January 20, 2009, in the United States as the fourth single, while it was promoted internationally as the third single. The single, originally written for Knowles, was rumored to have been later offered for Leona Lewis. Also, Kelly Clarkson, who worked with Tedder for her album All I Ever Wanted in 2008, claimed that Tedder used the same musical arrangement as that of "Halo" on her song "Already Gone", released in 2009. Lauded by contemporary pop critics, the song was later modified into a tribute to Michael Jackson following his death, and also as a tribute to the victims of the 2010 Haiti Earthquake, which Knowles sang on the television broadcast Hope for Haiti Now: A Global Benefit for Earthquake Relief featuring Chris Martin from Coldplay on the piano. The song topped the charts of Brazil, Norway and Slovakia and reached the top five in countries like Australia, Canada, Czech Republic, Germany, Ireland, New Zealand, Spain, Switzerland, the United Kingdom and the United States. "Halo" won Best Song at the 2009 MTV Europe Music Awards, and Best Female Pop Vocal Performance at the 52nd Grammy Awards, where it was also nominated for Record of the Year.