The Seymour Medal has been awarded by the Society for American Baseball Research to the best book of baseball history or biography published in the preceding year, since 1996. It is named in honor of Harold Seymour and Dorothy Seymour Mills, who were baseball historians.
- 1996: Fleet Walker's Divided Heart by David Zang; "Life of baseball's first black major-leaguer."
- 1997: Honus Wagner, The Life of Baseball's "Flying Dutchman" by Arthur D. Hittner; "Biography of a superstar and his remarkable career as a batter and shortstop with the Pittsburgh Pirates."
- 1998: The Detroit Tigers: Club and Community, 1945-95 by Patrick Harrigan; "Shows how the club evolved as an integral part of the city."
- 1999: Baseball's Last Dynasty: Charlie Finley's Oakland A's by Bruce Markusen; "Focuses on the emergence of a championship club despite its internal turmoil."
- 2000: Baseball's Pivotal Era, 1945-1951 by Bill Marshall; "Focuses on the events and colorful characters of the transformative postwar era."
- 2001: Past Time: Baseball as History by Jules Tygiel; "A collection of essays exploring baseball's role in American cultural and social history."
- 2002: Early Baseball and the Rise of the National League by Tom Melville; "An original assessment of the forces that developed early baseball into an organized national sport."
- 2003: Breaking the Slump: Baseball in the Depression Era by Charles C. Alexander; "During the Dark Thirties, baseball brightened the days for participants as well as spectators."
- 2004: Baseball Fever: Early Baseball in Michigan by Peter Morris; "A well-researched study of Michigan baseball from the 1830s to the 1870s."
- 2005: Negro League Baseball: The Rise and Ruin of a Black Institution by Neil Lanctot; "The rise of black baseball with focus placed on the economics rather than the feats of the players."
- 2006: Baseball Before We Knew It by David Block; "An amazing journey through time to discover the true evolution of our modern pastime."
- 2007: Game of Inches: The Stories Behind the Innovations That Shaped Baseball by Peter Morris
- 2008: Branch Rickey: Baseball's Ferocious Gentleman by Lee Lowenfish
- 2009: Chief Bender's Burden by Tom Swift; on the silent struggles of a Native American baseball star of the 1900s.
- 2010: Satchel: The Life and Times of an American Legend by Larry Tye; "an exhaustively well-researched look at one of the most intriguing personalities of the 20th century."
- 2011: 1921: The Yankees, the Giants, and the Battle for Baseball Supremacy in New York by Lyle Spatz and Steve Steinberg
- 2012: Fenway 1912: The Birth of a Ballpark, a Championship Season, and Fenway's Remarkable First Year by Glenn Stout, "celebrates the 100th anniversary of the opening of Fenway Park, and contains a detailed account of the 1912 World Series."
- 2013: Banzai Babe Ruth: Baseball, Espionage, & Assassination During the 1934 Tour of Japan, by Robert K. Fitts, "the story of the famous trip of an American League all-star team, featuring Babe Ruth, Lou Gehrig, Jimmie Foxx and Lefty Grove, which barnstormed Japan in November 1934."
- 2014: Smoky Joe Wood: The Biography of a Baseball Legend, by Gerald C. Wood, "chronicles his life and colorful career of Joe Wood from his youth in Ouray, Colorado all the way to his receipt of the degree of Doctor of Humane Letters from Yale President (and later Commissioner of Major League Baseball) A. Bartlett Giamatti in 1985 when he was 95 years old."
- 2015: Mover & Shaker: Walter O'Malley, the Dodgers and Baseball's Westward Expansion, by Andy McCue, "covers all the important elements in the life of the legendary and controversial baseball executive (Walter O'Malley) from his birth in the Bronx, New York, in 1903 to his death at the Mayo Clinic in Rochester, Minnesota, in 1979."
- 2016: Billy Martin: Baseball's Flawed Genius, by Bill Pennington, "an exhaustive, insightful, and balanced biography of one of baseball's most controversial managers (Billy Martin)."
- 2017: The Eighth Wonder of the World: The Life of Houston's Iconic Astrodome, by Robert C. Trumpbour and Kenneth Womack, "demonstrates the Astrodome's role in transforming Houston from an oil and cow town to a world-class city and considers the iconic stadium's impact on all subsequent stadium construction."