Doctor Rellan was a Vulcan female serving as a Starfleet doctor in the 23rd century.

In 2269, she was assigned to Starbase 25 as the station's Chief Medical Officer.

During this period, she treated the severely-injured Ensign Trinh following her transfer from the USS Enterprise. She informed Trinh of the extent of the injuries she had sustained on R-836 as well as the condition she would be in for the remaining few years of her life.

Rellan was on duty in the starbase's infirmary when Lieutenant Hikaru Sulu came to visit Trinh, though he instead spoke to Nurse Garcia, whom he believed would be better able to discuss the non-physical aspects of his girlfriend's condition. (TOS novel: Allegiance in Exile)