The dangerous situation was reported at 2:26 a.m. in the L.A. River just south of Glendale Boulevard, according to the Los Angeles Fire Department.
A passerby had called for help after discovering the man and woman surrounded by fast-moving storm water on a small island in the river, where officials say is at or near where they apparently lived.
A Swift Water Rescue team tethered an inflatable rescue boat to a secure area and brought the people to safety in 65 minutes while an LAFD helicopter searched the area to make sure no other people or pets were in danger, authorities say.
The rescued people declined transport to a hospital and were released at the scene.
City News Service contributed to this report.