Several Founding Fathers signed both the Declaration of Independence and the Constitution, but one notable example is James Wilson. He was a signatory of the Declaration of Independence in 1776 and also a major participant in drafting and signing the U.S. Constitution in 1787. James Wilson is one of only six people who signed both founding documents, highlighting his important role in the early United States government.
Other Founding Fathers who signed both documents include Roger Sherman and Benjamin Franklin, among a few others.
In summary, James Wilson is a key Founding Father who signed both the Declaration of Independence and the Constitution.