The former NYPD Blue actor will join the FX drama's fifth season in a major recurring role, reports Deadline.
Smits will play Latino gangbanger Neron "Nero" Padilla, who is said to become a dangerous mentor for Dax (Charlie Hunnam).
Sons of Anarchy was recently renewed for a sixth and possible seventh season by FX.
Creator Kurt Sutter has said that he is interested in developing a prequel series.
Smits previously played bad guy Miguel Prado in a season-long role in Dexter, for which he earned an Emmy nomination.
The fourth season of Sons of Anarchy concluded on December 6. 13 new episodes are expected to air in late 2012.
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