Justin Salt was a fictional character in the New Zealand soap opera Shortland Street. He is portrayed by Heath Jones.

Justin works as a surgeon for Justine Jones at Shortland Street Hospital.

Justin first appeared in 2006, when Libby Jeffries was looking for the perfect husband. She was drunk and working late on a report when he walked in. He tried to rape her. Justin then became a somewhat cocky antagonist who irritated Claire Solomon and Libby Jeffries. One night at The IV, when he goes too far, troubled amnesiac and barman Kieran Mitchell intervenes, revealing a dormant volatile nature. The violence escalates when Kieran convinces Claire to assist him in kidnapping Justin to teach him a lesson. They bring him to a garden shed behind their home and under duress he repents for his behaviour. He was later discovered by Jay Copeland bound in the trunk of a car.

Originally a character brought in to expose the dark and unpredictable nature of Kieran, he later developed into a prime suspect for Claire's murder investigation. It seems apparent that he recognizes Claire's voice from the night of the kidnapping, and he comments at one point that her perfume smells familiar to him too. His initials, J. S. appeared in Claire's diary as well as his lighter turning up in her bag the morning she was found dead.