Let It Go is the solo mini album debut of South Korean singer Heo Young-saeng of boy band SS501. The EP of Korean-language songs was released on May 12, 2011 under B2M Entertainment and distributed by LOEN Entertainment. The album was released in Taiwan on July 1, 2011 under Warner Music Taiwan.

Heo Young-saeng left SS501's former agency, DSP Media, in mid-2010 and signed with B2M Entertainment in October 2010, together with bandmate Kim Kyu-jong, to embark on his solo career. Both singers then held a joint fan meeting called Kyu Jong & Young Saeng Story In Seoul on December 4, which continued in Hong Kong, Japan, and other countries in Asia. During this tour, they both mentioned their plans to release their respective solo albums the following year.

Following Park Jung-min and Kim Hyung-jun of SS501, Heo was the third to debut as a solo artist after leaving his former agency in 2010. In April, B2M Entertainment announced that Heo's album release would be delayed due to an injury he sustained on his right hand during a dance practice. His plan to officially debut on April 28 and appear in his first solo performance on Mnet's M Countdown the same day was also postponed. Similarly, he appeared on SBS' Running Man only briefly instead of guest-starring on the show on May 8, 2011.

While still recovering from his injury, Heo decided to release a mini album on May 12. On May 4, B2M uploaded a 25-second music video teaser of Heo's upcoming title track, "Let It Go", on YouTube. A photo teaser was also released, showing a pale-colored image of Heo wearing a white polo shirt and black tie, using a motion blur to give the impression of movement.

On May 12, 2011, one week after the music video teaser release, Heo Young-saeng officially released his debut solo mini album, Let It Go. A 3-minute, 47-second music video of his dance song "Let It Go" was uploaded on YouTube the same day. Heo personally chose the mid-tempo dance song "Let It Go" as the title track for his debut album. As the main vocalist of SS501, he mostly sings ballads, and wanted to challenge himself and try new genres. The title track features Hyuna's rap, but new artist Park Ju-hyun (who was later revealed to be debuting as a Spica member under the same agency) was the one who appeared in the official music video and who performed Hyuna's rap parts on stage during Heo's live performances. Production costs for the music video, which filmed in Namyangju, reportedly reached USD$100,000.

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