HD 46375 b is an extrasolar planet located approximately 109 light-years away in the constellation of Monoceros, orbiting the star HD 46375.
With 79 Ceti b on March 29, 2000, it was joint first known extrasolar planet less massive than Saturn orbiting a normal star.
In this case the orbital distance is only a tenth that of the planet Mercury.
No transit of the planet has been detected, so its inclination must be less than 83°.
Because the inclination is unknown, the true mass of the planet is not known.