Charles Joseph Singer (2 November 1876 – 10 June 1960) was a British historian of science, technology, and medicine.
Singer was born in Camberwell in London, where his father Simeon Singer was a rabbi and Hebraist. He was educated at City of London School, University College London, and Magdalen College, Oxford (Zoology 1896-99, Honorary Fellow 1953). Trained in zoology and medicine, he qualified for medical practice in 1903. He was appointed medical officer on an expedition led by Sir John Harrington to the border region between Abyssinia and Sudan on the same day his medical qualification was announced. He returned to England and took a position at Sussex County Hospital in Brighton, and in 1907 left for Singapore. Forced to return to England on his father's death in 1908, he held positions at various hospitals in London until he moved to Oxford in 1914 to work with Sir William Osler (first Baronet), then Regius Professor of Medicine at the university.
Singer was married in July 1910 to Dorothea Waley Cohen, distinguished in her own right as an historian of the Medieval period. She provided valuable assistance in his publications for the remainder of his life. In the period leading up to World War I, Singer published several monographs, for which he was awarded the D.Litt. degree by Oxford.