Louis Legrand, S.S. (b. Lusigny-sur-Ouche, Burgundy, 12 June 1711, d. at Issy, Île-de-France, 21 July 1780) was a French Sulpician priest and theologian, and a Doctor of the Sorbonne.
Appointed director of studies in 1767 he exercised in this capacity an influence over young seminarians of France, who were preparing to take their degrees at the Sorbonne.
As a Doctor of the Sorbonne he was called upon to take a prominent part in framing the decisions and censures of the theological faculty; in that intense period of opposition to Christian dogma, he was centrally involved in its defense.
It was Legrand who wrote the condemnation of Jean-Jacques Rousseau's Emile, or On Education (reprinted in Migne's Theologiae Cursus Completus, II, col. 1111–1248).
The most important are: Parts of Legrand's Tractatus de Ecclesia have been reproduced by Migne in his Scripturae Sacrae Cursus Completus, IV.