Browder - known for his roles in sci-fi series Farscape and Stargate SG-1 - will appear in a Western-themed Who episode as a cowboy.
"He's great in it," Smith told Entertainment Weekly. "He brings that sort of American naturalism which we Brits just don't have, however hard we try.
"He makes a good cowboy. He has that great drawl. And the wonderful Adrian Scarborough (The King's Speech) is in that [too], he just steals the whole episode. He's fantastic."
Browder's episode - titled 'A Town Called Mercy' - is currently expected to air as the third episode of Doctor Who's seventh run.
"We went out and shot in Almeria in Spain, where they shot The Good, the Bad and the Ugly, A Fistful of Dollars - all the Sergio Leone stuff," Smith explained.
"You know, we've done Utah, we've done a great big Western, we've done New York. I think it's very exciting to see just where else it can go."
The 29-year-old actor claimed that each future Who episode resembles "a big film-of-the-week".
He said: "We've got dinosaurs on a spaceship. We've got a Western episode. We've got New York and Weeping Angels. And I think that's quite exciting. It's like going to the box office every week."
Doctor Who will return to BBC One in August.