Baron Vivian, of Glynn and of Truro in the County of Cornwall, is a title in the Peerage of the United Kingdom. It was created in 1841 for the soldier Sir Hussey Vivian, 1st Baronet. He had already been created a Baronet, of Truro in the County of Cornwall, in 1828. His eldest legitimate son, the second Baron, represented Bodmin in the House of Commons and served as Lord Lieutenant of Cornwall. His son, the third Baron, served as British Ambassador to Italy from 1891 to 1893. The latter's great-grandson, the sixth Baron, was a soldier and a Conservative member of the House of Lords. Lord Vivian was one of the ninety elected hereditary peers that were allowed to remain in the House of Lords after the passing of the House of Lords Act 1999. He was succeeded by his son, the seventh and (As of 2010[update]) present holder of the titles.
Sir Robert Vivian, illegitimate son of the first Baron, was also a prominent soldier. Another member of the Vivian family was Henry Vivian, 1st Baron Swansea. He was the nephew of the first Baron. Lord Swansea's younger brother was Sir Arthur Vivian.
A number of Vivian family graves with Celtic-style headstones can be found at the Parish Church of St Winnow.