Thomas Lennard, 1st Earl of Sussex, 15th Baron Dacre, (13 May 1654 – 30 October 1715) was an English peer.

He was the son of Francis Lennard, 14th Baron Dacre (1619–1662) and the former Elizabeth Bayning (1624–1686), who was created suo jure Countess of Sheppey for life in 1680.

Among his siblings were sisters, Elizabeth Lennard (the wife of William Brabazon, 3rd Earl of Meath and the Hon.

His 1677 accounts include an item which refers to £3 being paid to him when he went to a cricket match being played at "ye Dicker" (sic), which was then a common in the vicinity of Hailsham in East Sussex.

After Lady Barbara's death in 1741, the abeyance was terminated in favor of his younger daughter Anne, who became suo jure 16th Baroness Dacre.