Jean-Baptiste Henri-Dominique Lacordaire, OP, often styled Henri-Dominique Lacordaire, was a French ecclesiastic, preacher, journalist, theologian and political activist. He re-established the Dominican Order in post-Revolutionary France. Lacordaire was reputed to be the greatest pulpit orator of the nineteenth century.

The Order of Preachers, also known as the Dominican Order, is a Catholic mendicant order of pontifical right that was founded in France by a Castilian priest named Dominic de Guzmán. It was approved by Pope Honorius III via the papal bull Religiosam vitam on 22 December 1216. Members of the order, who are referred to as Dominicans, generally display the letters OP after their names, standing for Ordinis Praedicatorum, meaning 'of the Order of Preachers'. Membership in the order includes friars, nuns, active sisters, and lay or secular Dominicans. More recently, there has been a growing number of associates of the religious sisters who are unrelated to the tertiaries.