Justin Godart was born into a working-class family in Lyon on 26 November 1871. Godart was educated at the Collège-lycée Ampère and gained a Doctor of Law there. In 1904, Godart was elected the sixth deputy mayor of Lyon as a member of the Radical Party. In 1906, Godart became a Deputy of the French National Assembly, representing Lyon. From 1915 to 1918, Godart served as the Undersecretary of State for War in charge of the armed forces medical service. When Édouard Herriot became Prime Minister of France in 1924, Godart was appointed as the Minister for Labour, Hygiene, Welfare Work, and Social Security Provisions. Godart's time in this position came to an end with Herriot's ousting the next year. In 1926, Godart became a Senator, representing the department of Rhone. In 1932, Godart became the Minister of Public Health, again under Herriot. However, Godart did not remain in this position for long, as Herriot again lost power that December.