Which thinker influenced the Declaration of Independence the most?

Most scholars today believe that Jefferson derived the most famous ideas in the Declaration of Independence from the writings of English philosopher John Locke. Locke wrote that all individuals are equal in the sense that they are born with certain "inalienable" natural rights. That is, rights that are God-given and can never be taken or even given away. Among these fundamental natural rights, Locke said, are "life, liberty, and property." Jefferson adopted John Locke's theory of natural rights to provide a reason for revolution. He then went on to offer proof that revolution was necessary in 1776 to end King George's tyranny over the colonists.

Source: Constitutional Rights Foundation