in 2003, but with no details regarding the orbit or the companion's nature. An X-ray emission with a luminosity of has been detected at the star's position, which may be coming from a short-period, low-mass companion.

There are two common proper motion companions to 40 Leonis, NLTT 23781 and NLTT 23782, with a combined magnitude of 16.48, a spectral class of M5 and a wide angular separation from the primary