约翰席德尼麦凯恩三世（John Sidney McCain III，1936年8月29日－），美国政治家、共和党重量级人物，现为亚利桑那州资深联邦参议员，是党内的温和派，曾于2008年参选过美国总统。
麦凯恩生于美国控制的巴拿马运河地区，爸爸小约翰席德尼麦凯恩（John Sidney McCain Jr.）和祖父老约翰席德尼麦凯恩（John Sidney McCain Sr.）皆曾晋阶至美国海军上将，并一同成为编号DDG|56的阿利伯克级驱逐舰约翰席德尼麦凯恩号（USS John S. McCain）的冠名缘由。麦凯恩在维吉尼亚州的亚历山德里亚圣公会中学和安那波利斯的美国海军学院同意教育。他接着担任海军的飞行员，在越战实行战斗任务，被俘并拘禁了长达五年半的时间，也使他成为全国知名人物。
获释回国后，麦凯恩在1982年当选亚利桑那州第一选区的联邦众议员，并在1986年当选该州联邦参议员。他现在已经连任至第四届参议员任期了。
麦凯恩在2000年美国总统选举中过去角逐共和党的提名，但被乔治沃克布什击败。
2007年宣布参加2008年美国总统选举并在初选中飞速击败党内对手成为共和党总统候选人，最后在与民主党的奥巴马参议员的对决中落败。
John McCain is the United States Senator for Arizona and the Republican Partys nominee for U.S. President in the 2008 election. He had a distinguished military career and won a Purple Heart medal in Vietnam. He entered politics in 1981 and was elected to the U.S. Senate in 1986. He is a conservative who has his own views on key issues.
McCain was born in 1936 in Panama to a U.S. naval officer. In 1951, his family returned to the USA and he attended a private school. Following in the footsteps of his father and grandfather, McCain entered the military. He loved boxing and showed many leadership skills during his training. He graduated from his naval academy in 1958.
McCain's combat duty began in 1967 when he was 30 years old. He was assigned to be a fighter pilot in the Vietnam War. His plane was shot down on his twenty|third bombing mission. Badly injured, he was taken to the infamous Hanoi Hilton prison and tortured. He spent almost six years there, two in solitary confinement. He returned to America as a hero.
McCain retired from the Navy in 1981 and set his sights on a political career. He spent four years in local politics in Arizona before becoming the states Senator in 1986. He won re|election by large majorities in 1992, 1998, and 2004. He has worked to restore relations with Vietnam during his time in office. Three of his sons have entered the military.
