Mervyn Tuchet, 4th Earl of Castlehaven

Mervyn Tuchet, 4th Earl of Castlehaven; 14th Baron Audley; 2nd Baron Audley of Hely (d. 2 November 1686), was the son of Mervyn Tuchet, otherwise Audley, 2nd Earl of Castlehaven and his first wife, Elizabeth Barnham (1592 - about 1622).

He married Mary Talbot (buried 15 Mar 1710/1), daughter of John Talbot, 10th Earl of Shrewsbury (before 1601-1654) and of his wife née Mary Fortesque.

They had two children:

• Mary
• James (-1700)

He succeeded his brother as Earl of Castlehaven on 11 October 1686.

{| border="2" align="center" |- |width="30%" align="center"|Preceded by:
James Tuchet |width="40%" align="center"|Earl of Castlehaven |width="30%" align="center"|Followed by:
James Tuchet |}