詹姆斯·诺克斯·波尔克（James Knox Polk，1795年11月2日－1849年6月5日），第11任美国总统，任期自1845年3月4日至1849年3月4日。波尔克出生于北卡罗来纳州梅克伦堡县的派恩维尔，但他大部分时光是在田纳西度过的。民主党人士。就任总统前曾当过众议院议长（1835-1839）和田纳西州州长（1839－1841）,是唯一担任过众议院议长的美国总统。

波尔克是安德鲁·杰克逊的坚定支持者，并且是美国内战之前最后一位“强势”总统。波尔克因其成功的外交政策而出名。他曾扬言要与不列颠开战，之后退而与英国瓜分了西北地区的所有权。由于成功领导了美墨战争，知名度进一步上升。他降低了关税，并制定了一套一直沿用到1913年的财政制度。在作为“黑马”赢得1844年的选举后，他是第一位没有寻求连任而直接退休的总统。任期结束三个月后，因染霍乱去世。

James Knox Polk (November 2, 1795 – June 15, 1849) was the 11th President of the United States (1845–49). Polk was born in Mecklenburg County, North Carolina. He later lived in and represented Tennessee. A Democrat, Polk served as the 13th Speaker of the House of Representatives (1835–39)—the only president to have served as House Speaker—and Governor of Tennessee (1839–41). Polk was the surprise (dark horse) candidate for president in 1844, defeating Henry Clay of the rival Whig Party by promising to annex the Republic of Texas. Polk was a leader of Jacksonian Democracy during the Second Party System. His nickname was "Young Hickory" because of his close association with "Old Hickory", Andrew Jackson.