WASP-45 is a K-type main-sequence star about 701lk=onNaNlk=on away. The star's age cannot be well constrained, but it is probably older than the Sun. Yet, WASP-45 is enriched in heavy elements compared to the Sun, having 240% of the solar abundance.
The star has low ultraviolet emission, therefore it is suspected to have a low starspot activity, although chromospheric activity was reported elsewhere.
There is a companion star at a separation of 4.4 arcseconds, corresponding to 929 AU.
In 2011 a transiting hot Jupiter planet, WASP-45b, was detected. The planet equilibrium temperature is . No Rayleigh scattering was detected in the planetary atmosphere, implying the existence of hazes or a high cloud deck.