He attended Dongshin University as a student majoring in Broadcast Entertainment, under a full scholarship, along with three other members of Beast.

[6][7] Yoon enlisted for his mandatory military service as ROK Army on August 24, 2018,[8][9] and was discharged on April 10, 2020.

[11] Before his debut with Beast, Yoon auditioned for High Kick Through the Roof and was offered a role in the sitcom, but he turned it down to focus on his music career.

[13] Yoon was then chosen to model on an advertisement for premium jeans brand Buckaroo along with Shin Se-kyung.

[14] He was also featured for G.NA's song "I'll Back Off So You Can Live Better" music video along with fellow Beast member, Junhyung.

[27] On May 1, 2021, Highlight’s agency Around Us Entertainment announced, “Yoon Doojoon has been confirmed to appear in the drama There is No Goo Pil Soo, which will begin filming in July.”[28]