Upsilon Octantis (Upsilon Oct), Latinized from υ Octantis, is a solitary star in the southern circumpolar constellation Octans. It is faintly visible to the naked eye with an apparent magnitude of 5.75 and is located 343 light years away from the Solar System. However, it is receding with a heliocentric radial velocity of .
Upsilon Oct has a stellar classification of K0 III, indicating that it is a red giant. At present it has 2.12 times the mass of the Sun but has expanded to 10.3 times its girth. It shines with a luminosity of from its enlarged photosphere at an effective temperature of, giving a yellowish orange hue when viewed at night. Upsilon Oct has a solar metallicity, with an iron abundance equivalent to the Sun's. It spins leisurely with a poorly-constrained projected rotational velocity of .