The famed snapper – credited with discovering Kate Moss as a teenager – passed away on Friday (27Aug10), according to Britain’s Guardian newspaper.
After turning her back on modelling, Day forged a successful photography career in the 1990s, famously snapping Moss at the age of 16 for hip magazine The Face – the shoot which launched the supermodel’s career.
She also took the cover picture for Moby’s 1999 album Play and helped her boyfriend Mark Szaszy shoot music videos.
Day was diagnosed with a brain tumour in the late 1990s and she photographed her experiences in hospital for her 2001 book Diary.
She was given the all-clear from the disease but the tumour returned in 2008.
Moss and her other friends rallied around and raised more than $150,000 (£100,00) to pay for specialised chemotherapy in a clinic in Arizona, but sadly the treatment was unsuccessful and Day lost her fight for life on Friday.
Her funeral will take place on Friday (03Sep10) in Buckinghamshire, England. She is survived by her partner Szaszy.