Robert Carswell Lowther Sr. (December 14, 1923 – March 23, 2015) was an American professional basketball player. He played for the Tri-Cities Blackhawks and then the Waterloo Hawks in the National Basketball League during the 1948–49 season. Lowther averaged 1.9 points per game.
Lowther was also an accomplished track and field athlete, placing in the top 3 of the USA Outdoor Track and Field Championships in the triple jump and decathlon.