John Campbell, 3rd Earl of Breadalbane and Holland KB (10 March 1696 – 26 January 1782), styled Lord Glenorchy from 1716 until 1752, was a Scottish peer, diplomat and politician who sat in the House of Commons from 1727 to 1746.

He was appointed Master of the Jewel Office in 1745 and resigned his seat in the House of Commons.

He succeeded his father as Earl of Breadalbane and Holland on 23 February 1752 and became a Scottish representative peer.

He graduated as a Doctor of Civil Law (DCL) at the University of Oxford in 1756, and served as Justice in Eyre south of the Trent from 1756 to 1765 and Vice-Admiral of Scotland from 1776.

Lady Amabel died on 2 March 1726 leaving 2 children: The Earl married a second time to Arbella Pershall on 23 January 1730.