Constans II (November 7, 630 – September 15, 668), also called Constantine the Bearded (Kōnstantinos Pogonatos), is Byzantine Emperor from 641 to 668.

He is the last emperor to serve as consul, in 642.

Constans is a diminutive nickname given to the Emperor, who had been baptized Herakleios and reigns officially as Constantine.

The nickname establishes itself in Byzantine texts and has become standard in modern historiography.