In baseball, a batter who bats left handed (and thus stands on the left side of home plate as viewed by the pitcher), or a pitcher who throws with the left arm.

A Left-handed individual.

Phil Mickelson, a professional golfer.

Lefty or leftie, a political epithet for those on the political left.

Steve Carlton, a former professional baseball player.

Lefty Gomez, a professional baseball pitcher

Lefty shock, a front shock found on some Cannondale bicycles.

Lefty Frizzell, a country music performer.

Lefty Grove, a professional baseball pitcher

Benjamin "Lefty Guns" Ruggiero, member of the New York City Mafia

Lefty (album), an 1988 album by Art Garfunkel

Frank "Lefty" Rosenthal, sports handicapper and inspiration for Robert de Niro's character Sam Rothstein in Martin Scorsese's Casino

Lefty (protein) is a protein, which regulates the TGF beta signaling pathway.

Meaning of Scaevola, a nickname given to Gaius Mucius Scaevola after he engulfed his right hand in flames

Lefty (1964 film), an animated Soviet film directed by Ivan Ivanov-Vano

Lefty the Salesman, a Sesame Street character