The 43-year-old actor also took a selfie with the real-size wax figure which coincidentally was also dressed in similar outfit, reported Ace Showbiz.
"This is happenstance, but it is kind of crazy how kind of identical we decided to dress. I'm referring to him as a human being as if he dressed himself," Hamm said.
"A lot of people would say this kind of describes my acting on 'Mad Men'. A lot of waxy stares, a lot of silent brooding," he said.
Hamm's girlfriend Jennifer Westfeldt was also present.
Hamm is currently busy promoting his upcoming movie 'Million Dollar Arm' which hits US theatres on May 16.