The season is to air in the United Kingdom first but an exact premier date has not been announced.
Benedict Cumberbatch plays Holmes, while Martin Freeman plays Watson.
"They're fantastic," "Masterpiece" Executive Producer Rebecca Eaton told EW.com about the new episodes. "They are jaw dropping. They are like small movies. Benedict and Martin are so in their Sherlock-Watson groove. They are so comfortable with that relationship it's like being in the room with them."
"We are hugely excited about this next series of 'Sherlock,' and have worked closely with our partners, 'Masterpiece' and PBS, to bring these episodes to U.S. audiences in January. We promise our fans that Season 3 is worth waiting for," "Sherlock" executive producer Sue Vertue said in a statement.
Cumberbatch and Freeman have both collaborated on "The Hobbit" trilogy of films, as well.