Dokar Boyle wata ka’ida ce ta ilimin kimiyyar lissafi wadda ta bayyana cewa, a yanayin zafi akai-akai, matsewar iskar gas ya saba da karfinsa. Wato yayin da iskar iskar gas ke raguwa, karfinsa yana karuwa daidai gwargwado, yayin da karfin ya karu, karfin yana raguwa daidai gwargwado. Sunan dokar ne bayan Robert Boyle, masanin kimiyyar lissafi kuma masanin kimiya na Irish wanda ya fara bayyana ta a shekara ta 1662. Ana kuma kiran dokar Boyle a wani lokaci da dokar Boyle-Mariotte ko kuma dokar Mariotte.