The Miami Vice actor has been offered the role of plantation owner Spencer Bennett by director Quentin Tarantino, according to Deadline.
In the film, the newly-freed slave Django (Jamie Foxx) and bounty hunter Dr King Schultz (Christoph Waltz) meet Bennett while searching for a bounty, before being double crossed by him.
Django Unchained will also star Leonardo DiCaprio, Kurt Russell and Samuel L Jackson.
Don Johnson was cast in new NBC comedy series A Mann's World earlier this year.
> Quentin Tarantino casts Dennis Christopher in Django Unchained
Watch the trailer for Quentin Tarantino's last movie Inglourious Basterds below: