Lagache is a surname. Notable people with the surname include:
Alfred Lagache (1889 –1971), French professional three-cushion billiards player André Lagache (1885–1938), French racing driver Daniel Lagache (1903–1972), French physician, psychoanalyst and professor at the Sorbonne
See also Chardon Lagache (Paris Métro), station on the Paris Métro Monchy-Lagache, commune in the Somme department in Hauts-de-France in northern France