Ahn Se-ha made his screen debut in 2013 in the tvN series She Is Wow. That same year, he landed a minor role in the movie Hope, which was based on a true story. The movie was hailed Best Film at the 34th Blue Dragon Film Awards. In 2015, he appeared in the MBC romantic comedy She Was Pretty, which earned him a Best Supporting Actor nomination at the MBC Drama Awards. In 2016, he was cast in the hit KBS2 sageuk Moonlight Drawn by Clouds, which recorded a peak viewership rating of 23.3 percent. In 2017, he was nominated for a Golden Acting Award at the MBC Drama Awards for his work in the romantic comedy 20th Century Boy and Girl. In 2021, he acted a supporting role in JTBC’s Sunbae, Don’t Put On that Lipstick.

Ahn Se-ha married his girlfriend of over a year on May 14, 2017.