According to The Sun, Kirke will play Moordale’s new head after Mr Groff (Alistair Petrie) is forced to depart from the school following the events of the second season.
It is reported the actor was incredibly keen to join the show and will live in Wales for the duration of the six month shoot.
RadioTimes.com has reached out to Netflix asking for comment.
Although she is most famous for her role as Jessa Johansson on Girls, Kirke has also appeared in a number of independent films and had a recurring role in Netflix series Maniac in 2018.
If the reports are true, she will join an already impressive Sex Education cast that includes Gillian Anderson as sex therapist Jean Milburn and Asa Butterfield as her son and lead character Otis, as well as breakout stars such as Emma Mackey and Ncuti Gatwa.
Production on the third series is currently underway, having previously been postponed as a result of the coronavirus pandemic, and is expected to arrive on Netflix towards the start of 2021.
The series has attracted a devoted following since its 2019 debut, with viewers particularly invested in the central will-they-wont-they romance between awkward Otis (Butterfield) and cool girl Maeve (Mackey).
The series has also been praised for tackling themes of adolescent sexuality in a refreshingly honest and entertaining way, while its unusual blend of a UK setting and American high school aesthetic as well as its jukebox soundtrack have proven immensely popular.
Seasons one and two of Sex Education are currently streaming on Netflix. Check out the best series on Netflix and best movies on Netflix to keep you entertained or visit our TV Guide for more to watch.