"This I Promise You" is a ballad by American boy band NSYNC. It was released in September 2000 as the third and final single in the United States and the fourth and final single in Europe from their third studio album, No Strings Attached, in 2000. The song is included on all three of the band's compilation albums: Greatest Hits (2005), The Collection (2010), and The Essential *NSYNC (2014). The single reached number five on the US Billboard Hot 100.

A Spanish language version of the song, titled "Yo te Voy a Amar", was recorded at the same time for Spanish-speaking countries.

Richard Marx was asked by A&R executive David Novik if he had any songs that he could give to NSYNC. He specifically requested a ballad.^[2] Initially, the song was written with a three-person girl group in mind. Marx quickly finished the song writing the harmonies specifically for NSYNC.^[2]

Marx would later record the song twice, first for the Japanese release of his album Days in Avalon similar to the NSYNC version, and again as a rock song for the European version of his Stories to Tell album. Marx would later use the Days in Avalon version of "This I Promise You" for his Now and Forever: The Ballads album as a duet with Asian singer Sabrina.^{[citation needed]}

"This I Promise You" was the group's fifth top-ten single in the U.S., reaching number five on the Billboard Hot 100 chart in the autumn of 2000. In addition, the song spent 13 weeks at number one on the Billboard Adult Contemporary chart, the group's first and only song to do so.^[3] Internationally, the song reached number twenty-one on the UK Singles Chart.

A Spanish language version of the song, titled "Yo te Voy a Amar" was recorded at the same time and released in Spanish-speaking countries such as Mexico, Colombia, Venezuela, Peru, Chile, Bolivia, Paraguay, Uruguay, Argentina, Ecuador, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica, Panama, Cuba, Dominican Republic, and Spain.

Irish Westlife lead singer Shane Filan included his version of this song on his third solo album Love Always in 2017. This served as a buzz single which was first released online and later released with a music video exclusively available in Europe. He dedicated this song to his wife Gillian.^[6]

Personnel^[1]

• Richard Marx – songwriter, producer, arranger
• David Cole – recording engineer, mixing engineer
• Adam Barber – vocal recording
• Cesar Ramirez – assistant engineer
• Ok Hee Kim – assistant engineer
• Toby Dearborn – assistant engineer
• Jeffrey CJ Vanston – drum and keyboard programming
• Michael Thompson – guitar
• Chaz Harper – mastering

• List of Billboard Adult Contemporary number ones of 2000 and 2001 (U.S.)