Isaacs – who famously portrayed Lucius Malfoy in the Harry Potter franchise – will play Peter Groff, Mr Groff’s “more successful and not very modest oldest brother” who Mr Groff (Alistair Petrie) is living with following his split from his wife, Maureen (Samantha Spiro).
Kirke – previously in HBO’s Girls – will star as the new headmistress Hope, a former Moordale student with grand plans to restore the school’s reputation.
Recording artist and songwriter Saleh will make her acting debut as Cal, a nonbinary student at Moordale who “instantly clashes with Hope’s new vision for the school”.
Saleh’s Cal is confirmed to be a recurring character while Kirke and Isaacs will be guest stars on Netflix’s hit comedy-drama.
Season two of Sex Education was released in January. Production on the highly anticipated third season began earlier this month in Wales.
Season three is expected to arrive on the streaming platform in 2021. An exact release date is yet to be confirmed.