Kepler-186 is a main-sequence M1-type dwarf star, located 177.5 parsecs (579 light years) away in the constellation of Cygnus.

It is a BY Draconis variable changing brightness slightly, probably from star-spots, with a period of 33.695 days.

[11] The possibility that the signals in the light curve of the star were actually from something else has been ruled out by an investigation with the W. M. Keck and Gemini Observatories, using speckle imaging and adaptive optics techniques, which, while unable to resolve the planets, were able to rule out other possibilities than the system of planets.

Because of the very slow evolution of red dwarf stars, the age of the Kepler-186 system is poorly constrained, although it is likely to be greater than a few billion years.

[13] Conjectures involving the Titius–Bode law, (and the related Dermott's law) indicate that there could be several remaining planets to be found in the system - two small ones between e and f and another larger one outside of f.[15] That hypothetical outer planet must have an orbital radius beyond 16.4 AU for planetary system to remain stable.