John Byron Nelson, Jr. (February 4, 1912 – September 26, 2006) was an American PGA Tour golfer between 1935 and 1946.

He and two other well known golfers of the time, Ben Hogan and Sam Snead, were born within 6 months of each other in 1912. Although he won many tournaments in the course of his relatively brief career, he is mostly remembered today for having won 11 consecutive tournaments and 18 total tournaments in 1945. He retired officially at the age of 34 to be a rancher, later becoming a commentator and lending his name to the HP Byron Nelson Championship, the first PGA Tour event to be named for a professional golfer. In 1974, Byron Nelson received the Bob Jones Award, the highest honor given by the United States Golf Association in recognition of distinguished sportsmanship in golf.

He became the second recipient of the PGA Tour Lifetime Achievement Award in 1997, and was inducted into the World Golf Hall of Fame. in 1974. He received the 1994 Old Tom Morris Award from the Golf Course Superintendents Association of America, GCSAA's highest honor. Nelson received the Congressional Gold Medal shortly after his death in 2006.