The collection includes personal and professional correspondence, scripts, movies, photographs and posters.
The university said they would be housed at the Attenborough Centre for the Creative Arts to give them "as wide an audience as possible".
Lord Attenborough, a former chancellor of the university, died in August 2014.
The archive has been stored at the family home in London until recently.
A spokeswoman for the University of Sussex said it expected to receive the collection in the "next few months", it would then be catalogued before being made available to the public and for academic study.
Lord Attenborough's son, Michael Attenborough, said: "I felt my father would have been so thrilled to know that his work will live on in this way.
"It is fitting that his personal papers will come to rest in a place that will ensure his legacy is upheld with genuine care and internationally recognised expertise."
The University of Sussex's arts centre was recently given a multi-million pound makeover and renamed after Lord Attenborough, who was chancellor from 1998 until 2008.
A portrait of Lord Attenborough which includes names of high profile Hollywood and British entertainment figures who helped fund the refurbishment has been unveiled at the centre.
"We are hugely honoured to be chosen to house this prestigious and historically important archive of Lord Attenborough's work," said the University of Sussex vice-chancellor Professor Michael Farthing.
Born in Cambridge in 1923, Lord Attenborough appeared in films such as Brighton Rock, The Great Escape and 1993 dinosaur blockbuster Jurassic Park.
His directorial highlights include the 1982 film Gandhi, which won eight Academy Awards, including best film and best director.
Thousands of personal items and work papers belonging to Oscar-winning director Richard Attenborough are being loaned to the University of Sussex.