Thomas Lynch, Jr. (August 5, 1749 – unknown) was a signer of the United States Declaration of Independence as a representative of South Carolina; his father was unable to sign the Declaration of Independence, because of illness.
At an early age, young Thomas Lynch, Jr., was sent to a flourishing school, The Indigo Society School, at that time maintained at Georgetown, South Carolina. Before he was thirteen, his father removed him from this school and sent him to England, to enjoy those higher advantages which that country presented to the youth of America. Having passed some time in the collegiate institution of Eton, he entered Cambridge, and received his degree. He left Cambridge to study at the Middle Temple in London.
After returning from his studies abroad, he soon married, on May 13, 1772, a young lady he had known since childhood, Elizabeth Shubrick, daughter of Thomas and Mary Baker Shubrick, of Charleston, SC. They had no children. 
Interestingly, Elizabeth’s sister, Mary, married Edward Rutledge, and her sister, Hannah, married William Heyward, brother of Thomas Heyward, Jr. Rutledge and Thomas Heyward, Jr., were also signers of the Declaration.
Lynch, Jr. became a company commander in the 1st South Carolina regiment in 1775.
In 1776, he learned he father had resigned his seat in Congress due the sudden and incapacitating illness from a paralyzing stroke in Philadelphia,
The Provincial Assembly elected young Lynch to fill it, and he hastened to Philadelphia to take his seat in 1776. Lynch and his father thus had the unique distinction of being the only father-son team of representatives to the Congress.
He supported the proposition for independence and impressed his colleagues with his earnestness and eloquence. Lynch voted for the Declaration, and on August 2, 1776, three days before his 27th birthday, he joined the other South Carolina delegates in signing the parchment, leaving a space between the signatures of Edward Rutledge and Thomas Heyward, Jr., for an additional signature, in the hope of the elder Lynch making enough recovery one day to also sign the document.
During his military service in 1775, he was exposed to malarial mosquitoes and the fever, from which he never fully recovered.
In 1779 he retired from public life and lived on at Peachtree Plantation on the Santee River with his wife. Following the advice of his doctors, in 1779 he and his wife decided to travel to France with the hope that therapeutic help there may restore his health. On this first leg of the long journey, their ship was last seen when it was but a few days out at sea. Presumably it foundered during a storm and they both drowned, no one survived; ship and passengers and crew all simply disappeared, another mystery of the fabled “Bermuda Triangle” area. 
At age 26, he was among the youngest to sign the Declaration; at age 30, he was the youngest of the Signers at their deaths.
Having had no children, this Signer has no direct descendants.
His will was made before the fateful journey and includes provisions for his sisters and step-mothe. It also requires that no one would inherit Lynch land unless “they shall take and use the Surname Lynch and no other…it having been my father’s intention and it being my meaning to limit a part of his estate as far as the law will permit to such of his family as shall use the surname ‘Lynch’….”.
Mr. Lynch’s nephew, John Lynch Bowman later changed his name to John Bowman Lynch, he was the only son of the Signer’s sister, Sabina. John Bowman Lynch had three sons and four daughters, all three sons were killed in Confederate service during the Civil War, and left no descendants.