The Colloquy at Poissy was a religious conference which took place in Poissy, France, in 1561. Its object was to effect a reconciliation between the Catholics and Protestants (Huguenots) of France.
The conference was opened on 9 September in the refectory of the convent of Poissy, the French king (aged 11) himself being present. It broke up inconclusively a month later, on 9 October, by which point the divide between the doctrines appeared irreconcilable.
The Calvinist faction in France, though less than half a million in number, was strong and vocal, under the guidance of several princes of the royal blood and members of the higher nobility. The spread of Protestantism and the application of its fundamental principle of private judgment produced far-reaching differences in belief. To heal these and so bring about unity, a conference was held at Weimar in 1560, between the Lutherans Viktor Striegel (1524-1569) and Flacius, on free will.
The Poissy conference was arranged by Catherine de' Medici, the Florentine Catholic queen-mother and regent during the minority of her son, Charles IX of France, with the support of the Chancellor Michel de l'Hôpital and the lieutenant-general of the kingdom, Anthony of Navarre. The heads of the Catholic party had attempted to frustrate any form of negotiation.
Disaffection towards the Holy See had paralysed French Catholic activity. The Council of Trent, a general council, was in session under the presidency of Pope Pius IV, but voices were heard even among the French bishops, advocating the convocation of a separate national synod. Instead, Catherine and her advisers chose a religious conference under the direction of the civil power. The Pope tried to prevent, what under the circumstances had to be construed by Catholics as, the defiance of his ecclesiastical authority.