John Peter Kleinow (July 20, 1877 – October 9, 1929) was a reserve catcher in Major League Baseball who played from 1904 through 1911 for the New York Highlanders (1904–10), Boston Red Sox (1910–11) and Philadelphia Phillies (1911).

Listed at 5 ft 10 in (1.78 m), 165 lb., Kleinow batted and threw right-handed.

In an eight-season career, Kleinow was a .213 hitter (354-for-1665) with three home runs and 135 RBI in 584 games, including 146 runs, 45 doubles, 20 triples and 42 stolen bases.

Kleinow died in New York City at age 52.

This biographical article relating to a United States baseball catcher born in the 1870s is a stub.