[6] On February 11, 2010, Heo was featured on the soundtrack for The Woman Who Still Wants to Marry, singing a duet with Han Ye-ji in the song "One Two Three".

In October 2010, Heo Ga-yoon was one of twenty idols from different South Korean groups that recorded the song, "Let's Go", for the purpose of increasing public participation in the 2010 G-20 Seoul summit.

Heo recorded "Wind Blow" for the soundtrack of MBC's My Princess; the song was released on January 5, 2011.

Heo made her acting debut on I'm a Flower Too with a cameo appearance as a high school student.

As part of Mystic White, Ga-yoon released the charity song "Mermaid Princess" on December 26, 2012.

In 2014, HyunA, Ga-yoon, and Sohyun released the song "Only Gained Weight" for Brave Brothers' tenth anniversary album in January.

In September, Gayoon became an MC for the third season of OnStyle's fashion program Style Log, together with Beast's Lee Gi-kwang and Do Sang Woo.

In 2015, Gayoon released an OST for SBS's Yong-pal called "Nightmare" together with Yong Jun-hyung on August 18.

In November, it was revealed that Gayoon will make her big screen debut with the movie Father, Daughter.

[19] On June 13, 2016, Cube Entertainment announced that 4Minute decided to disband and the members were still in discussions on renewing their contracts.