He was born in Beyoğlu district of Istanbul. He loved reading and writing ever since he learned the letters. Sezer Ün started writing stories, poems and plays in high school, and when his interest in language and literature increased, he decided to study literature and studied at Kültür University, Department of Turkish Language and Literature.
After four years of study, he started to work as a teacher. He completed his master's degree in Turkish Language at Marmara University Institute of Turkish Studies. A few of his stories appeared in various magazines and his first book was published in 2019.
The author's books published by Beyaz Balina Publications in 2021 are titled What Happened to the Letters, Chess Club, and A Night in the Monkey Forest.