Ariel S. Ballif Jr. (May 29, 1926 – April 21, 1994) was a prominent stage designer. He was one of the founders of Theatre 138, the first "alternative" theater in Salt Lake City.
Ballif was born in Rexburg, Idaho. His father was Ariel S. Ballif and his mother was Arta Romney, a daughter of George S. Romney and a sister of Marion G. Romney. His younger brother Jae, was a professor and administrator at Brigham Young University (BYU).
Ballif received his bachelors degree from BYU in 1948, and his MFA from Yale University in 1952. He later served on the theater faculty at the University of Utah and designed major productions for many organizations, including Ballet West and the Utah Opera. With Tom Carlin and Stu Falconer, Ballif operated Theatre 138 in Salt Lake City from 1966 to 1986.