Jonni is a first name for Finnish men. The name day for Jonni falls on March 29, which is shared with Jouni, Joni, Joonas, Joona, and Jonne. Both Jonni and Jonne are variations of the name Johannes, which corresponds to the English name John or the Scandinavian name Jon.

According to the Digital and Population Data Services Agency, by the end of 2019, 725 individuals have been named Jonni.