Thomas Heyward Jr. was an Episcopalian.
From: Robert G. Ferris (editor), Signers of the Declaration: Historic Places Commemorating the Signing of the Declaration of Independence, published by the United States Department of the Interior, National Park Service: Washington, D.C. (revised edition 1975), page 76:
In 1779 Heyward was wounded during Brig. Gen. William Moultrie's repulse of a British attack on Port Royal Island, along the South Carolina coast near Heyward's home. The following year, the British plundered White Hall and carried off all the slaves. When they took Charleston, they captured Heyward, who as helpless to defend the city. He was imprisoned at St. Augustine, Fl., until July 1781. Shortly before his release, he celebrated Independence Day by setting patriotic verses to the British national anthem. "God save the King" because "God save the thirteen States," a rendition that soon echoed from New Hampshire to Georgia.
...he died in 1809 at the age of 62 and was interred in the family cemetery at Old House Plantation.
Note that numerous sources and authoritative references have been consulted in order to ascertain the religious affiliation of the American Founding Fathers. Note that the excerpts and references mentioned on this page are not the only references used in order to identify this person's religious affiliation.