He served as Solicitor-General and then as a judge, and ultimately as Chief Justice of the Common Pleas.
Eyre was the eldest son of Sir Samuel Eyre of New House, Whiteparish, Wiltshire and his wife Martha Lucy, daughter of Francis Lucy of Westminster and Brightwalton, Berkshire.
At the 1698 English general election, he was returned as Member of Parliament for Salisbury.
[4] Eyre was returned to Parliament again at the 1708 British general election and was appointed Solicitor-General from 1708 to 1710.
In 1718, he gave an opinion favouring the view of the Prince of Wales, rather than that of the king over the education of the prince's children, and was therefore passed over for promotion to be Lord Chief Justice of King's Bench.