One of the best games in Mira's collegiate career came as a junior in 1962 in the Gotham Bowl against the Nebraska Cornhuskers. Despite playing in 20 °F (−7 °C) weather in front of fewer than a thousand fans at Yankee Stadium, Mira threw for 321 yards, a Miami school record at the time, and was named the bowl game's most valuable player. Despite Mira's efforts, the Cornhuskers won by two points, 36–34. The previous year, the Hurricanes lost by a point to Syracuse in the Liberty Bowl.
At the start of the 1963 season Mira was the cover story for Sports Illustrated's college preview issue. The article, written by Key West native John Underwood, was titled "One Wonderful Conch is this Mira," and featured many anecdotes about Mira's life growing up and becoming a star on the small island.
With the Birmingham Americans of the new World Football League (WFL) in 1974, he was MVP of their championship game victory, completing 155 of 313 passes for 2,248 yards and 17 touchdowns and 14 interceptions during the season. Despite the success on the field, the Birmingham franchise folded in March. In 1975, with the Jacksonville Express of the WFL, he completed 123 of 254 passes for 1,675 yards and 12 touchdowns and interceptions. The league would cease operations late in the 1975 season.
Mira returned to Florida and now operates the Native Conch, a food concession at Fairchild Botanical Gardens in Coral Gables.  For many years he owned a Key West restaurant called George Mira's Pizza Huddle, located across the street from the junior league baseball fields where it became a haven for post-game celebrations.