Guillaume Marie Charles Henri Mollat (1 February 1877 – 4 May 1968) was a French prelate and historian.

[1] He studied at the Day School for Children Nantais, then entered the Saint-Sulpice Seminary in Paris in 1896, before completing his theological studies at the French Seminary in Rome.

He thereafter integrated the École des hautes études and the Vatican School of Palaeography.

In 1933, he won the Prix of the Académie française for his work La question romaine de Pie VI à Pie XI.

He was elected a member of the Académie des Inscriptions et Belles-Lettres in 1954.