"Sun Will Never Set" (Chinese: 日不落) is a song by Taiwanese singer Jolin Tsai, featured on her ninth studio album Agent J.

[4] By June 2, 2007, media outlets revealed that Tsai had completed the album's recording and had traveled to London for a ten-day dance course.

In response, EMI's General Manager for Greater China, Sam Chen, stated: "IFPI Taiwan has requested the police to investigate, and any uploads, downloads, or exchanges will be prosecuted in accordance with our standard policy.

Tsai expressed her disappointment, saying, "I spent over a year and a lot of effort on this album, and it saddens me that people don't respect intellectual property rights.

However, after learning from his ex-girlfriend—who was a fan of Tsai—that Tsai would be studying abroad in the United Kingdom, Tsui decided to write a romantic love song infused with British elements.

"[9] On September 21, 2007, Tsai released her ninth studio album, Agent J, which featured the song "Sun Will Never Set".

[22] On January 10, 2008, Tsai appeared on the Southeast TV's variety show Love from the Strait and performed the song.

[25] On April 28, 2008, she took the stage at the 4th China International Cartoon & Animation Festival Opening Ceremony, where she performed the song once more.