Skins are optional alternate appearances to characters that can be unlocked in Sly Cooper: Age of Thieves. The only way to unlock skins is by finding the respective Secret Masks of each of the five main playable characters (Sly, Carmelita, Murray, Bentley, and Penelope). Finding all of the Secret Masks in a time period will allow that era's ancestor to have an alternate skin based on one of the ancestors from the previous game, Sly Cooper: Thieves in Time.
- Slytunkhamen: "Tennessee Kid" Cooper Skin
- Slaigh: Caveman "Bob" Cooper Skin
- Henriette: Salim Al-Kupar Skin
- Thaddeus: Sir Galleth Cooper Skin
- Otto: Rioichi Cooper Skin