Lawrence Brainerd (March 16, 1794 – May 9, 1870) was an American businessman, abolitionist and United States Senator from Vermont. A longtime anti-slavery activist, after leaving the Jacksonians in the 1830s, Brainerd was active in the Whig, Liberty, and Free Soil parties, and was one of the organizers of the Republican Party when it was formed as the main anti-slavery party in the mid-1850s. Brainerd's longtime commitment to the cause of abolition was recognized in 1854, when opponents of slavery in the Vermont General Assembly chose him to fill a five-month vacancy in the United States Senate.