"Lefty" Lew Tendler (September 28, 1898, in Philadelphia, Pennsylvania – November 5, 1970, in Atlantic City, New Jersey) was an American boxer.

The statistical boxing website BoxRec lists Tendler as the tenth ranked lightweight of all time, while The Ring Magazine founder Nat Fleischer placed him at #9.

[5][1] In an important early career win, Tendler decisively defeated future world bantamweight champion Pete Herman on February 28, 1916, in six rounds, repeatedly scoring points with his right.

Herman had difficulty mounting an effective defense, and bled from his nose through much of the bout where he caught frequent rights from Tendler.

On October 1, 1917, Tendler defeated future world junior lightweight champion Johnny Dundee in a close six-round newspaper decision in Philadelphia.

Tendler took the lead in most of the fighting, used his reach advantage to dominate at long range, and landed more blows to take the decision.

Tendler first defeated fellow Jewish boxer Frankie Callahan, another leading contender for the lightweight title, on July 6, 1918, in an eight-round newspaper decision in Atlantic City.

In three other meetings, Tendler won a six-round newspaper decision in Philadelphia, a ninth-round technical knockout in Boston where Callahan broke his wrist, and a rough fifth-round technical knockout at an open-air arena in Lawrence, Massachusetts, on September 18, 1920, where Callahan told his manager he had broken a rib in the second round.

Leonard excelled in the speed and precision of his attack, while still managing to ward off most of his opponent's blows, particularly Tendler's strong left.

Leonard demonstrated his mastery of ring tactics against an opponent who became sluggish, and was unable to mount the offensive he had shown in their bout the previous July.

[17][18][19] Tendler first defeated Sailor Friedman, a highly rated lightweight, on December 16, 1921, in an eight-round newspaper decision at New York's Madison Square Garden.

[20] In three previous meetings that year, on September 13, August 24, and February 28, Tendler won in newspaper decisions in Milwaukee, and Philadelphia.

Tendler defeated reigning world light heavyweight champion Pinky Mitchell in their last meeting on February 18, 1924, in a close ten-round newspaper decision in Milwaukee.

[22] Tendler fell to Mickey Walker in a ten-round unanimous decision on June 2, 1924, in an attempt at the National Boxing Association (NBA) world welterweight championship.

[24] In one of his last bouts with a top talent on July 16, 1925, Tendler drew with future world welterweight champion Joe Dundee by decision, in ten fast and hard-fought rounds before 10,000 at Shibe Park in Philadelphia.

[28] Tendler died on November 7, 1970, at Shore Memorial Hospital in Somers Point, a suburb of Atlantic City, New Jersey, of an arterial clot.