Philip Montagu D'Arcy Hart, CBE (25 June 1900 – 30 July 2006) was a seminal British medical researcher and pioneer in tuberculosis treatment.
Philip D'Arcy Hart was the grandson of Samuel Montagu, 1st Baron Swaythling.
He was a pioneer of evidence-based medicine, conducting some of the earliest randomized controlled trials on patulin in 1943 and streptomycin with Austin Bradford Hill.
D'Arcy Hart became involved with much of the MRC's early research into dust diseases in coal miners.
At the age of 71, D'Arcy Hart published a seminal paper in the Journal of Experimental Medicine, showing that the intracellular pathogen Mycobacterium tuberculosis avoids destruction in the cell's lysosomes by circumventing these organelles altogether—a trick now known to be used by many other intracellular pathogens.