Łoziński was born into a lowly noble family, his father Walerian working as postmaster and mandate administrator.

He attended a gymnasium in Sambor, where he first started writing, and it was there that he finished his first, never published novel titled Kamień w Spasie.

Not wanting to be a financial burden to his parents, he moved to Lwów (modern Lviv, Ukraine) where his cousin, Karol Szajnocha, took him in and found him a job in the official editorial office of the Gazeta Lwowska where he furthered his writing career.

On January 10, 1861, Łoziński entered a saber duel with Karol Cieszewski, a well-known and popular journalist from Lwów, his editorial colleague.

His funeral, which took place on February 2, became a great patriotic demonstration attended by the entire Polish intelligentsia of Lwów.