Joel Lake’s review published on Letterboxd:
The honest look at a young girl dealing with her sexuality in a coming of age story that is ingrained in the genre while also breaking away from the genre(thanks to a unique story that takes an honest look at a young woman's relationship with an older man without condoning or approving of said relationship) and connecting with the powerful story thanks to the great performance newcomer actress Bel Powley brings to the film. The infusion of creative art is smooth and fun. The film is not perfect, but if you're looking for a coming of age film that breaks away from the normal cookie cutter look most of these films take on, Diary of a Teenage Girl will fill that role for you. It just might be too abstract for a wide audience. Good overall, but not great.