Leonard Harold Barker III (born July 7, 1955)[1] is an American former Major League Baseball right-handed starting pitcher.

On April 16, 1978, at Fenway Park, Barker (then with the Texas Rangers) threw a pitch that sailed upward onto the screen above and behind the backstop.

Barker's perfect outing, one of only twenty four in the history of Major League Baseball, is also the most recent no-hitter thrown by an Indians pitcher.

During the 1983 season, Barker was traded to the Atlanta Braves for Brett Butler, Brook Jacoby, Rick Behenna and $150,000 cash.

[1] The trade was initiated by the Braves, who were in a tight race for first in the National League West Division with the Los Angeles Dodgers.

After the season, the Braves signed Barker to one of the richest contracts for a pitcher in baseball history to that time, $4 million over five years.

Barker served as the head coach for Division II Notre Dame College in South Euclid until the school's closure in 2024.