This is a list of seasons of Major League Baseball.
| Year | National League champion | 
|---|---|
| 1876 | Chicago White Stockings | 
| 1877 | Boston Red Caps | 
| 1878 | |
| 1879 | Providence Grays | 
| Year | National League champion | American Association champion | Union Association champion | World's Championship Series champion | 
|---|---|---|---|---|
| 1880 | Chicago White Stockings | – | – | – | 
| 1881 | – | – | – | |
| 1882 | Cincinnati Red Stockings | – | – | |
| 1883 | Boston Beaneaters | Philadelphia Athletics | – | – | 
| 1884 | Providence Grays | New York Metropolitans | St. Louis Maroons | Providence Grays (3–0) | 
| 1885 | Chicago White Stockings | St. Louis Browns | – | Tie, Chicago White Stockings and St. Louis Browns (3–3–1) | 
| 1886 | – | St. Louis Browns (4–2) | ||
| 1887 | Detroit Wolverines | – | Detroit Wolverines (10–5) | |
| 1888 | New York Giants | – | New York Giants (6–4) | |
| 1889 | Brooklyn Bridegrooms | – | New York Giants (6–3) | 
| Year | National League champion | American Association champion | Players' League champion | World's Championship Series / Temple Cup champion | 
|---|---|---|---|---|
| 1890 | Brooklyn Bridegrooms | Louisville Colonels | Boston Reds | Tie, Louisville Colonels and Brooklyn Bridegrooms (3–3–1) | 
| 1891 | Boston Beaneaters | Boston Reds | – | – | 
| 1892 | – | – | Boston Beaneaters (5–0–1) | |
| 1893 | – | – | – | |
| 1894 | Baltimore Orioles | – | – | New York Giants (4–0) | 
| 1895 | – | – | Cleveland Spiders (4–1) | |
| 1896 | – | – | Baltimore Orioles (4–0) | |
| 1897 | Boston Beaneaters | – | – | Baltimore Orioles (4–1) | 
| 1898 | – | – | – | |
| 1899 | Brooklyn Superbas | – | – | – | 
| Year | American League champion | National League champion | World Series / Chronicle-Telegraph Cup champion | 
|---|---|---|---|
| 1900 | – | Brooklyn Superbas | Brooklyn Superbas (3–1) | 
| 1901 | Chicago White Stockings | Pittsburgh Pirates | – | 
| 1902 | Philadelphia Athletics | – | |
| 1903 | Boston Americans | Boston Americans (5–3) | |
| 1904 | New York Giants | – | |
| 1905 | Philadelphia Athletics | New York Giants (4–1) | |
| 1906 | Chicago White Sox | Chicago Cubs | Chicago White Sox (4–2) | 
| 1907 | Detroit Tigers | Chicago Cubs (4–0) | |
| 1908 | Chicago Cubs (4–1) | ||
| 1909 | Pittsburgh Pirates | Pittsburgh Pirates (4–3) | 
| Year | American League champion | National League champion | Federal League champion | World Series champion | 
|---|---|---|---|---|
| 1910 | Philadelphia Athletics | Chicago Cubs | – | Philadelphia Athletics (4–1) | 
| 1911 | New York Giants | – | Philadelphia Athletics (4–2) | |
| 1912 | Boston Red Sox | – | Boston Red Sox (4–3) | |
| 1913 | Philadelphia Athletics | – | Philadelphia Athletics (4–1) | |
| 1914 | Boston Braves | Indianapolis Hoosiers | Boston Braves (4–0) | |
| 1915 | Boston Red Sox | Philadelphia Phillies | Chicago Whales | Boston Red Sox (4–1) | 
| 1916 | Brooklyn Robins | – | Boston Red Sox (4–1) | |
| 1917 | Chicago White Sox | New York Giants | – | Chicago White Sox (4–2) | 
| 1918 | Boston Red Sox | Chicago Cubs | – | Boston Red Sox (4–2) | 
| 1919 | Chicago White Sox | Cincinnati Reds | – | Cincinnati Reds (5–3) | 
| Year | American League champion | National League champion | World Series champion | 
|---|---|---|---|
| 1950 | New York Yankees | Philadelphia Phillies | New York Yankees (4–0) | 
| 1951 | New York Giants | New York Yankees (4–2) | |
| 1952 | Brooklyn Dodgers | New York Yankees (4–3) | |
| 1953 | New York Yankees (4–2) | ||
| 1954 | Cleveland Indians | New York Giants | New York Giants (4–0) | 
| 1955 | New York Yankees | Brooklyn Dodgers | Brooklyn Dodgers (4–3) | 
| 1956 | New York Yankees (4–3) | ||
| 1957 | Milwaukee Braves | Milwaukee Braves (4–3) | |
| 1958 | New York Yankees (4–3) | ||
| 1959 | Chicago White Sox | Los Angeles Dodgers | Los Angeles Dodgers (4–2) | 
| Year | American League champion | National League champion | World Series champion | 
|---|---|---|---|
| 1960 | New York Yankees | Pittsburgh Pirates | Pittsburgh Pirates (4–3) | 
| 1961 | Cincinnati Reds | New York Yankees (4–1) | |
| 1962 | San Francisco Giants | New York Yankees (4–3) | |
| 1963 | Los Angeles Dodgers | Los Angeles Dodgers (4–0) | |
| 1964 | St. Louis Cardinals | St. Louis Cardinals (4–3) | |
| 1965 | Minnesota Twins | Los Angeles Dodgers | Los Angeles Dodgers (4–3) | 
| 1966 | Baltimore Orioles | Baltimore Orioles (4–0) | |
| 1967 | Boston Red Sox | St. Louis Cardinals | St. Louis Cardinals (4–3) | 
| 1968 | Detroit Tigers | Detroit Tigers (4–3) | |
| 1969 | Baltimore Orioles | New York Mets | New York Mets (4–1) | 
| Year | American League champion | National League champion | World Series champion | 
|---|---|---|---|
| 1970 | Baltimore Orioles | Cincinnati Reds | Baltimore Orioles (4–1) | 
| 1971 | Pittsburgh Pirates | Pittsburgh Pirates (4–3) | |
| 1972 | Oakland Athletics | Cincinnati Reds | Oakland Athletics (4–3) | 
| 1973 | New York Mets | Oakland Athletics (4–3) | |
| 1974 | Los Angeles Dodgers | Oakland Athletics (4–1) | |
| 1975 | Boston Red Sox | Cincinnati Reds | Cincinnati Reds (4–3) | 
| 1976 | New York Yankees | Cincinnati Reds (4–0) | |
| 1977 | Los Angeles Dodgers | New York Yankees (4–2) | |
| 1978 | New York Yankees (4–2) | ||
| 1979 | Baltimore Orioles | Pittsburgh Pirates | Pittsburgh Pirates (4–3) | 
| Year | American League champion | National League champion | World Series champion | 
|---|---|---|---|
| 1990 | Oakland Athletics | Cincinnati Reds | Cincinnati Reds (4–0) | 
| 1991 | Minnesota Twins | Atlanta Braves | Minnesota Twins (4–3) | 
| 1992 | Toronto Blue Jays | Toronto Blue Jays (4–2) | |
| 1993 | Philadelphia Phillies | Toronto Blue Jays (4–2) | |
| 1994 | 1994–95 Major League Baseball strike | ||
| 1995 | Cleveland Indians | Atlanta Braves | Atlanta Braves (4–2) | 
| 1996 | New York Yankees | New York Yankees (4–2) | |
| 1997 | Cleveland Indians | Florida Marlins | Florida Marlins (4–3) | 
| 1998 | New York Yankees | San Diego Padres | New York Yankees (4–0) | 
| 1999 | Atlanta Braves | New York Yankees (4–0) | |
| Year | American League champion | National League champion | World Series champion | 
|---|---|---|---|
| 2000 | New York Yankees | New York Mets | New York Yankees (4–1) | 
| 2001 | Arizona Diamondbacks | Arizona Diamondbacks (4–3) | |
| 2002 | Anaheim Angels | San Francisco Giants | Anaheim Angels (4–3) | 
| 2003 | New York Yankees | Florida Marlins | Florida Marlins (4–2) | 
| 2004 | Boston Red Sox | St. Louis Cardinals | Boston Red Sox (4–0) | 
| 2005 | Chicago White Sox | Houston Astros | Chicago White Sox (4–0) | 
| 2006 | Detroit Tigers | St. Louis Cardinals | St. Louis Cardinals (4–1) | 
| 2007 | Boston Red Sox | Colorado Rockies | Boston Red Sox (4–0) | 
| 2008 | Tampa Bay Rays | Philadelphia Phillies | Philadelphia Phillies (4–1) | 
| 2009 | New York Yankees | New York Yankees (4–2) | 
| Year | American League champion | National League champion | World Series champion | 
|---|---|---|---|
| 2010 | Texas Rangers | San Francisco Giants | San Francisco Giants (4–1) | 
| 2011 | St. Louis Cardinals | St. Louis Cardinals (4–3) | |
| 2012 | Detroit Tigers | San Francisco Giants | San Francisco Giants (4–0) | 
| 2013 | Boston Red Sox | St. Louis Cardinals | Boston Red Sox (4–2) | 
| 2014 | Kansas City Royals | San Francisco Giants | San Francisco Giants (4–3) | 
| 2015 | New York Mets | Kansas City Royals (4–1) | |
| 2016 | Cleveland Indians | Chicago Cubs | Chicago Cubs (4–3) | 
| 2017 | Houston Astros | Los Angeles Dodgers | Houston Astros (4–3) | 
| 2018 | Boston Red Sox | Boston Red Sox (4–1) | |
| 2019 | Houston Astros | Washington Nationals | Washington Nationals (4–3) | 
| Year | American League champion | National League champion | World Series champion | 
|---|---|---|---|
| 2020 | Tampa Bay Rays | Los Angeles Dodgers | Los Angeles Dodgers (4–2) | 
| 2021 | Houston Astros | Atlanta Braves | Atlanta Braves (4–2) | 
| 2022 | Philadelphia Phillies | Houston Astros (4–2) | |
| 2023 | Texas Rangers | Arizona Diamondbacks | Texas Rangers (4–1) | 
| 2024 | New York Yankees | Los Angeles Dodgers | Los Angeles Dodgers (4–1) | 
| 2025 | Toronto Blue Jays | ||
| 2026 |