His mother, Nadezhda Zvenigorodskaya, is a stage actress, and his father, Valery Kozlovsky, was a professor at Moscow State University specializing in marketing and mass communications.

[6] He made his big screen debut in 1998, playing the troubled sixth grader Denis on the Russian television series Simple Truths.

Upon graduation, he matriculated to the Saint Petersburg State Theatre Arts Academy, entering the acting/directing course supervised by Lev Dodin.

The film, set during the time of the First World War, tells the story of two brothers who wish to build their own football stadium.

Kozlovsky received the Russian Guild of Film Critics "White Elephant Award" for the best male lead actor.

There he played the role of robber archaeologist Sergei Filatov, who is transported into the past together with his friends when making illegal excavations.

He played the lead role of Max Andreev, a young ambitious executive manager who begins to reevaluate his priorities in life and career.

He played Count Vorontzov in the film Matilda (2017), which told the story of the romance between Emperor Nicholas II and ballerina Mathilde Kschessinska.

Also in 2017, it was announced that Kozlovsky will appear as Oleg of Novgorod in the sixth season of popular Canadian historical drama Vikings.

They split shortly after Olga gave birth to their daughter Oda Valentina Zueva (born in February 2020).