Gugudan SeMiNa (Korean: 구구단 세미나) was the second official subgroup of South Korean girl group Gugudan, formed by Jellyfish Entertainment in 2018.

It was composed of three Gugudan members: Nayoung, Sejeong and Mina.

On June 29, Jellyfish Entertainment announced that Sejeong, Mina and Nayoung will form a unit group and release a single album on July 10.

[1] They first appeared as Jellyfish Entertainment trainees on Mnet's survival show Produce 101 with a performance of "Something New" by Nikki Yanofsky.

[2] On July 10, they released a self-titled single album featuring three tracks, including the lead single "SeMiNa.