John S. Armstrong (November 18, 1850 – April 26, 1908) was an American real estate developer. He was the co-founder (along with Thomas Marsalis) of the former City of Oak Cliff (now incorporated into Dallas) and founder of the town of Highland Park, Texas. Armstrong was also a founder of the State Fair of Texas. John Scarborough Armstrong was born November 18, 1850 in Nashville, Tennessee to J. W. and Pauline Armstrong. He was one of thirteen children. He married Alice J. White on July 3, 1878, in Lancaster, Kentucky.