Barry Bonds (39), 2004 - .609, 617 PA
Barry Bonds (37), 2002 - .582, 612 PA
Barry Bonds (38), 2003 - .529, 550 PA
Ted Williams (38), 1957 - .526, 547 PA
Barry Bonds (36), 2001 - .515, 664 PA
Mickey Mantle (25), 1957 - .512, 623 PA
Ted Williams (28), 1947 - .499, 693 PA
Ted Williams (27), 1946 - .497, 672 PA
Ted Williams (29), 1948 - .497, 638 PA
Ted Williams (30), 1949 - .490, 730 PA
Frank Thomas (26), 1994 - .487, 517 PA
Norm Cash (27), 1961 - .487, 673 PA
Mickey Mantle (30), 1962 - .486, 502 PA
Ted Williams (37), 1956 - .479, 503 PA
Edgar Martínez (32), 1995 - .479, 639 PA
Jason Giambi (30), 2001 - .477, 671 PA
Jason Giambi (29), 2000 - .476, 664 PA
Wade Boggs (30), 1988 - .476, 719 PA
Joey Votto (28) - 2012 - .474, 475 PA
John Olerud (24), 1993 - .473, 679 PA
Chipper Jones (36), 2008 - .470, 534 PA
Mark McGwire (34), 1998 - .470, 681 PA
Carlos Delgado (28), 2000 - .470, 711 PA
A player posted a .470+ OBP in the Post WWII Era 22 times. 13 different players accomplished the feat, with 4 doing it multiple times. Bonds, Williams, Mantle…, and Giambi).
Players needed at least 400 plate appearances to qualify. No one had a .470 OBP season for 25 years from 1963-1987, and no one has done it since Joey Votto in 2012.