2,2′-Bipyridine (bipy or bpy, pronounced /ˈbɪpiː/) is an organic compound with the formula (C5H4N)2.

This colorless solid is an important isomer of the bipyridine family.

It is a bidentate chelating ligand, forming complexes with many transition metals.

Ruthenium and platinum complexes of bipy exhibit intense luminescence.

[4] Although bipyridine is often drawn with its nitrogen atoms in cis conformation, the lowest energy conformation both in solid state and in solution is in fact coplanar, with nitrogen atoms in trans position.