KFC
Gaffigan replaces Norm MacDonald, who took over the role from Darrell Hammond in August of 2015.
Gaffigan will make his debut as the Colonel in an ad airing during CBS' pre-Super Bowl broadcast. The ad will air again during the second half of the game.
KFC hadn't used Colonel Sanders in advertising for 21 years before bringing him back in a new advertising campaign last May.
The ads have generated a mixed response from customers, with many saying they hate them.
But analysts and company executives have credited the marketing campaign with helping to boost sales in the US.
The chain's same-store sales grew 3% in fiscal 2015, after plunging more than 15% two years earlier.
"The brand's reinvigoration with Saturday Night Live alums playing the role of founder Colonel Sanders has brought some buzz back to the concept," Nomura analyst Mark Kalinowski wrote in a recent note.
Here's the new ad starring Gaffigan.
"If you looked at social media over Halloween, there were zillions of Colonel Sanders costumes - not just kids, but adults," Kevin Hochman, KFC's chief marketing officer, said at an event debuting Nashville Hot Chicken in New York City in January.
The new 30-second ad starring Gaffigan features Colonel Sanders waking from a nightmare in which Norm MacDonald has stolen the Colonel's identity and takes credit for coming up with KFC's new Nashville Hot Chicken, which was released earlier this year.
A second ad starring Gaffigan will be released later this month, the company said.