阿瑟·詹姆斯·贝尔福，第一代贝尔福伯爵，KG，OM，PC，DL（英语：Arthur James Balfour, 1st Earl of Balfour，1848年7月25日－1930年3月19日），英国保守党政治家。曾任首相，任期自1902年7月开始，1905年12月结束。后任外交大臣，任期自1916年开始，1919年结束。

贝尔福生于苏格兰，曾经接受哲学教育。1874年大选后，他首次进入国会。贝尔福初入政坛时，被人视为一个门外汉，直至1887年，他获任为爱尔兰布政司，表现出色，在1887年引入强制法，以针对爱尔兰土地战争期间出现的杯葛、恐吓和非法集会。

Arthur James Balfour, 1st Earl of Balfour, KG,OM,PC,DL (UK /ˈbælfə/; 25 July 1848 – 19 March 1930) was a British Conservative politician who was the Prime Minister of the United Kingdom from July 1902 to December 1905, and later Foreign Secretary.

Balfour came into a vast inheritance at 21. Entering Parliament in 1874, he achieved prominence as Chief Secretary for Ireland, in which position he suppressed agrarian unrest whilst taking measures against absentee landlords. He opposed Irish Home Rule, saying there could be no half-way house between Ireland remaining within the United Kingdom or becoming independent. From 1891 he led the Conservative Party in the House of Commons, serving under his uncle, Lord Salisbury, whose government won large majorities in 1895 and 1900.