"Mr. Taxi / Run Devil Run" is Girls' Generation's third Japanese single. It was released in three editions, two limited CD+DVD editions and a regular CD only edition.

CD+DVD editions come with a special photobook (1 type each) and the CD+DVD Deluxe First Press Edition also includes a bonus trading card. The second A-side, "Run Devil Run", which was previously released as their first Japanese digital single, is Japanese version of their second Korean album' title track Run Devil Run.