What is the real name of River Song?

River Song’s real name is Melody Pond. She was born to Amy Pond and Rory Williams after being conceived aboard the TARDIS, where exposure to the time vortex gave her some abilities associated with the Doctor’s species, the Time Lords.

The character was first introduced in “Silence in the Library” and “Forest of the Dead” as an archaeologist from the Doctor’s future. Her personal chronology runs in the reverse direction to the Doctor’s: events that are new to him may already be memories for her. This unusual structure is central to the mystery surrounding her identity and relationship with him.

“Let’s Kill Hitler” reveals that Melody Pond became Mels, Amy and Rory’s childhood friend, before regenerating into the adult River Song played by Alex Kingston. The name “River Song” is itself a translation of “Melody Pond” in a language where ponds do not exist and are rendered as rivers. River is therefore not Amy’s sister or another version of Amy, despite their close family connection.