John Nixon gave one of the first formal public readings of the Declaration of Independence in Philadelphia.
The reading took place at noon on July 8, 1776, in the yard of the Pennsylvania State House, the building now known as Independence Hall. Nixon was a Philadelphia official and public reader who presented the newly approved declaration to a gathered crowd.
Formal readings also occurred that day in Trenton, New Jersey, and Easton, Pennsylvania. These readings helped spread the document beyond Congress and made the declaration a public statement of separation from Great Britain.
John Hancock was president of Congress and signed the engrossed document, while Thomas Jefferson was its principal drafter. Neither man gave the Philadelphia reading described in this question.