Säyneinen is a village and a former municipality of Finland at the time of its existence in the Kuopio Province, now in Northern Savonia.

The name of Säyneinen comes from the word säyne, referring to the ide, a fairly common fish in Finland.

Another municipality named after this fish was Säynätsalo (via the local word säynät) in Central Finland.

[1] Unlike the names of most municipalities ending in -(i)nen, the declension of Säyneinen is in the singular: Säyneisen, Säyneisessä and not in the plural (*Säyneisten, *Säyneisissä).

Like the modern region of North Karelia, the area was initially part of the Novgorod Republic, passing to Muscovy with the rest of Novgorod in 1478 and remaining under Russian rule until the Swedish conquest of the area finalized by the Treaty of Stolbovo in 1617.