Bush took part in the final act of the club's annual revue, showing up on stage wearing a cowboy hat and singing about his return to Texas to the tune of "Green Green Grass of Home."
The president's tounge-in-cheek lyrics for the crowd included "Yes, you're gonna miss me, the way you used to quiz me, it's good to touch the brown brown grass of home."
Bush earned a standing ovation for his attempt at song.
The invitation-only Gridiron Club was founded in 1885 and is the oldest organization for Washington journalists.