Theodore Eustace (German: Theodor Eustach; 14 February 1659 – 11 July 1732) was the Count Palatine of Sulzbach from 1708 until 1732.

Theodore Eustace was born in Sulzbach in 1659 as the only surviving son of Christian Augustus, Count Palatine of Sulzbach and Amalie of Nassau-Siegen.

He died in Dinkelsbühl in 1732 and was buried in Sulzbach.

[citation needed] Theodore Eustace married Maria Eleonore of Hesse-Rothenburg (15 September 1675 – 27 January 1720), daughter of Landgrave William (sister of Ernest Leopold), and had the following children: