Dokar Bernoulli, wadda aka fi sani da ƙa'idar Bernoulli, ta bayyana cewa yayin da saurin ruwa ya ƙaru, matsa lamba a cikin ruwan yana raguwa. Sunan wannan ƙa'idar ne bayan Daniel Bernoulli, masanin lissafi na Switzerland a ƙarni na 18 wanda ya fara tsara ƙa'idar. Dokar Bernoulli tana da aikace-aikace da yawa a cikin ilimin kimiyyar lissafi, injiniyanci, da kuma aerodynamics, gami da ƙirar fuka-fukan jirgin sama, kwararar jini ta jijiyoyi da jijiya, da halayyar ruwa a cikin bututu da tashoshi.