It was established by Mary Adelaide Hare in 1916 as Dene Hollow School for the Deaf in Burgess Hill, West Sussex.

The school bought Arlington Manor and surrounding estates in 1947, and moved from its old site in Burgess Hill to the refurbished premises in 1949.

Several building projects have since followed, expanding the school to its current size, including a classroom block, school hall, boarding house for boys, staff flats (now boarding house for year seven pupils), new updated swimming pool, science block, sixth form campus, arts and design centre, Arlington Arts Centre which includes a theatre seating 250, music therapy centre, and recording studio.

The Mary Hare Foundation raised £4 million towards the project, and in 2021 they had the groundbreaking event and building commenced.

The building project was completed in August 2022 when the keys were officially handed from the contractors to Mary Hare, and in September 2022 the new Primary School opened for the first time.