U Hydrae is a single star in the equatorial constellation of Hydra, near the northern constellation border with Sextans. It is a semiregular variable star of sub-type SRb, with its brightness ranging from visual magnitude (V) 4.7 to 5.2 over a 450-day period, with some irregularity. This object is located at a distance of approximately 680 light years from the Sun based on parallax. It is drifting closer with a radial velocity of −26 km/s.