Pacat was born in Melbourne, Australia, and was educated at the University of Melbourne.[3] She[a] lived in several different cities including Perugia where she studied at Perugia University, and Tokyo, where she lived for five years.[4][2] Pacat wrote the Captive Prince trilogy around her day job as a translator while training as a geologist.[1]

Pacat is queer and genderqueer, using both she/her and he/him pronouns.[5] She identifies as "a proud wog,"[6] and states that this played an influence while writing the Captive Prince trilogy: "As for the influence on Captive Prince, I'm a bisexual wog, and Damen is a bisexual wog - so there's that[7]....There's a lot of wog-politics in the series, although its rarely read from that perspective outside of Australia."