第一代马尔博罗公爵约翰·丘吉尔，KG，PC（John Churchill, 1st Duke of Marlborough，1650年5月26日－1722年6月16日），英国军事家、政治家。靠着他妻子萨拉·詹宁斯（Sarah Churchill, Duchess of Marlborough）与安妮女王的私密友谊，以及他个人卓越的军事、外交才能，让他在1702年成为英国最有权力的男人。他在西班牙王位继承战争中名利双收，与战友欧根亲王共列为法国太阳王的两大克星，并使英国上升为一级的海陆强权，促成18世纪的繁荣兴盛。但是他贪婪投机的性格，既使他成为安妮时代最有钱的英国男性，却也减损他部分的声望。

General John Churchill, 1st Duke of Marlborough, Prince of Mindelheim, KG,PC (/ˈmɑːrlbərə/, often /ˈmɔːrlbrə/; 26 May 1650 – 16 June 1722 O.S.), was an English soldier and statesman whose career spanned the reigns of five monarchs. Rising from a lowly page at the court of the House of Stuart, he served James, Duke of York, through the 1670s and early 1680s, earning military and political advancement through his courage and diplomatic skill. Churchill's role in defeating the Monmouth Rebellion in 1685 helped secure James on the throne, yet just three years later he abandoned his Catholic patron for the Protestant Dutchman, William of Orange. Honoured for his services at William's coronation with the earldom of Marlborough, he served with further distinction in the early years of the Nine Years' War, but persistent charges of Jacobitism brought about his fall from office and temporary imprisonment in the Tower. It was not until the accession of Queen Anne in 1702 that Marlborough reached the zenith of his powers and secured his fame and fortune.