Argos was a planet located three or four galaxies away from the Pristatrek Galaxy. The Doctor once defeated Luminus there, and "averted a catalogue of disasters". (PROSE: Tragedy Day)
When the Tenth Doctor gave Gerry Hobbes-Mayhew a portable immersion heater, Kate Maguire asked whether he had got it from Planet Zog. The Doctor replied, "No. Argos." (PROSE: Autonomy)
Behind the scenes
In non-valid sources
The Doctor mentioned her sonic screwdriver had been made at Argos, which her companion Gayle Tuesday confused for the shop. (TV: Untitled).