There are several notable people with the surname Orenstein.
- Henry Orenstein, American poker player and entrepreneur
- Henry Orenstein (painter), Canadian artist
- Ian Orenstein, Canadian cartoonist and writer
- Joan Orenstein, Canadian actress
- Leo Orenstein, Canadian television producer and director
- Oscar Orenstein, Canadian artist
- Peggy Orenstein, American writer
- Zigu Ornea (born Orenstein or Ornstein), Romanian cultural historian