The comics were invited to announced the Chicago Cubs starting lineup before the team's game against the Miami Marlins.
Ferrell and Galifianakis kicked off the festivities by offering humorous introductions for the Cubs, including pointing out that first baseman Anthony Rizzo is "ironically" not Italian and that Bryan LaHair loves playing banjo.
The two actors appeared at the Cubs game to promote their upcoming political comedy The Campaign.
Ferrell and Galifianakis's new film sees them playing rival political candidates vying for a North Carolina Congressional seat.
The Campaign opens on August 10 in the US and September 28 in the UK.
Watch a trailer for The Campaign below: