Jean Ybarnegaray was born in Uhart-Cize, Department of Pyrénées-Atlantiques—then called Basses Pyrénées—in the Northern Basque Country. He studied law at the Sorbonne and Bordeaux University and practised as a lawyer. He was elected to the Chamber of Deputies in April 1914.
On the outbreak of the First World War he was recalled to service. He was wounded and discharged from the army with the Légion d'honneur, returning to the Chamber of Deputies where he criticised the Nivelle Offensive of 1917, the armistice of 1918, and the Treaty of Versailles.
He served in the first Vichy government, as Minister of State in the first government of Marshal Philippe Pétain, and as Minister for Veterans and the Family in the second Pétain government. He resigned his office on 6 September 1940.
Ybarnegaray had undertaken Resistance activities—assisting escapees in crossing the Pyrenees, for which he was arrested in 1943, and detained in Plansee in Tyrol. Although he was sentenced post-war to loss of civil rights, his resistance activities resulted in the sentence being suspended.
He died in Paris on 25 April 1956.
- Jolly, Jean (1960). "Dictionnaire des Parlementaires français 1889-1940" (in French). Presses Universitaires de France. Retrieved 2007-08-22.