First of all, it's extremely difficult to talk about "conservatives" in the 18th century and "conservatives" in the 21st century as though they were the same thing. In the 18th century, conservatism meant being pro-monarchy. Supporting a republic, as all the Founding Fathers did, was considered fundamentally liberal at the time.

That said, the U.S. political system in the 1790s was divided into two parties, the Federalists and the Democratic-Republicans. The Federalists are considered to have been the more right-wing of the two, with the major figures of the Federalist Party being Alexander Hamilton and John Adams.

However, the Federalist Party was incredibly different from today's Republican Party. For one thing, the Federalist Party's main position was that the U.S. needed to become more centralized whereas the current Republican Party tends to support decentralization. For another, the Federalists weren't very focused on religion as far as I know. The religious right has really only been a force in American politics since about the 1970s.

Perhaps John Adams:

He wrote (to Thomas Jefferson in 1813), “The general principles on which the fathers achieved independence were. . . . the general principles of Christianity. . . . I will avow that I then believed, and now believe, that those general principles of Christianity are as eternal and immutable as the existence and attributes of God; and that those principles of liberty are as unalterable as human nature.”

On the other hand, it was under his Presidency, in 1797. that the Treaty of Peace and Friendship with Tripoli was ratified, which states “The government of the United States of America is not in any sense founded on the Christian Religion” (Which does not, of course mean anything about his personal religious beliefs, but does indicate some support for the separation of church and state.)

He was a Federalist, so perhaps Conservative (though, as u/Bob9999999 indicated, it would be difficult to label any of the Revolutionary Founding Fathers as truly Conservative).

Sam Adams (of later Beer brand fame):

Was a Christian, writing, (in The Rights of the Colonists in 1772),

“The right to freedom being the gift of the Almighty…The rights of the colonists as Christians…may be best understood by reading and carefully studying the institutions of The Great Law Giver and Head of the Christian Church, which are to be found clearly written and promulgated in the New Testament”.

He was not a Conservative, however, being one of the more radical Revolutionaries.

Alexander Hamilton:

He was an Episcopalian and founder of The Christian Constitutional Society, to “First; Support the Christian Religion. Second; Support the United States. He was ‘Conservative’ amongst the Founding Fathers, being one of the main supporters of the Federalist tendency.

Patrick Henry:

He was incensed when he heard that people called him a deist. In a letter to his daughter in 1796, he said, “I think religion of infinitely higher importance than politics; and I find much cause to reproach myself that I have lived so long, and have given no decided and public proofs of my being a Christian. But, indeed, my dear child, this is a character which I prize far above all this world has or can boast.”

However, Patrick Henry was certainly not a conservative. He was one of the more radical Revolutionaries.

Franklin, Jefferson, Washington:

Were all deists, and dubiously Christian.

Alexander Hamilton or John Adams are the best candidates for Christian and “Conservative”.