According to this source and counting our own (The Milky way)it seems that five galaxies could be seen with the naked eye without the help of a telescope. The large and small Magellanic Clouds, the Andromeda Galaxy,and the Sagittarius Dwarf.
Posts: 6383 | Location: u.s.a, south Florida | Registered: 06-03-02
A bit of googling seems to exclude the Sagittarius Dwarf, a small fuzzy dot, which was not discovered until the mid-1990s. It was not seen because the Milky Way has stars which obscure it and because it is feint.
However, the Milky Way, and Andromeda (M31)are visible in the Northern Hemisphere and in the Southern Hemisphere the Large and Small Magellanic clouds are visible.