There are two galaxies on northern sky visible by naked eye: Andromeda M31 and and Triangle M33.
Related links:
1:β Andromedae AKA Mirach region, 2:M31 AND M33 AS SEEN FROM CENTRAL PA, 3:GAUGING LIGHT POLLUTION: THE BORTLE DARK-SKY SCALE, 4:THE EYES HAVE IT — DEEP-SKY OBSERVING WITHOUT EQUIPMENT, 5:DEEP-SKY OBSERVING WITHOUT EQUIPMENT, PART II — THE WINTER SKY, 6:HOW DARK IS YOUR NIGHT SKY?, 7:HOW TO SEE THE FARTHEST THING YOU CAN SEE