This is an incomplete list of people who have served as Lord Lieutenant of Hertfordshire. From 1660 the office holder was also Custos Rotulorum of Hertfordshire.

• William Parr, 1st Marquess of Northampton 1553 –
• Sir Ralph Sadleir 1570–?
• Henry Carey, 1st Baron Hunsdon 1583–1585
• Robert Dudley, 1st Earl of Leicester 3 July 1585 – 4 September 1588
• William Cecil, 1st Baron Burghley 31 December 1588 – 4 August 1598
• vacant
• Robert Cecil, 1st Earl of Salisbury 5 August 1605 – 24 May 1612
• William Cecil, 2nd Earl of Salisbury 10 July 1612 – 1642 jointly with
• Charles Cecil, Viscount Cranborne 31 March 1640 – 1642
• Interregnum
• Arthur Capell, 1st Earl of Essex 26 July 1660 – 1681
• John Egerton, 2nd Earl of Bridgewater 10 February 1681 – 26 October 1686
• Laurence Hyde, 1st Earl of Rochester 18 November 1686 – 1688
• Charles Talbot, 1st Duke of Shrewsbury 4 April 1689 – 1691
• Algernon Capell, 2nd Earl of Essex 3 February 1692 – 10 January 1710
• William Cowper, 1st Earl Cowper 26 August 1710 – 1712
• James Cecil, 5th Earl of Salisbury 26 June 1712 – 1714
• William Cowper, 1st Earl Cowper 5 March 1715 – 1722
• William Capell, 3rd Earl of Essex 11 October 1722 – 8 January 1743
• vacant
• William Clavering-Cowper, 2nd Earl Cowper 8 March 1744 – 18 September 1764
• William Capell, 4th Earl of Essex 12 November 1764 – 1771
• James Cecil, 1st Marquess of Salisbury 13 March 1771 – 13 June 1823
• James Grimston, 1st Earl of Verulam 5 July 1823 – 17 November 1845
• James Grimston, 2nd Earl of Verulam 17 January 1846 – 1892
• Edward Villiers, 5th Earl of Clarendon 23 August 1892 – 2 October 1914
• Thomas Brand, 3rd Viscount Hampden 9 February 1915 – 1952
• Sir David Bowes-Lyon 1 July 1952 – 13 September 1961^[1]
• Sir George Burns 8 December 1961 – 12 February 1986
• Sir Simon Bowes-Lyon 12 February 1986 – 27 July 2007^[2]
• Dione Grimston, Countess of Verulam 27 July 2007 – 31 July 2017^[3]
• Robert Voss 4 August 2017 – present^[4]

Deputy lieutenants

A deputy lieutenant of Hertfordshire is commissioned by the Lord Lieutenant of Hertfordshire. Deputy lieutenants support the work of the lord-lieutenant. There can be several deputy lieutenants at any time, depending on the population of the county. Their appointment does not terminate with the changing of the lord-lieutenant, but they usually retire at age 75.

• 1660 to 1682: Edward Harley
• 1662 to 1688: Humphrey Cornewall
• 1689 to 1700: Edward Harley
• 1694 to 1715: Thomas Harley

21st Century

• 9 November 2009: Howard Anthony Guard^[5]