| | Anaheim Angels, see Los Angeles Angels |
| 1 | Arizona Diamondbacks | 1998 | 2021 | 3,754 | 1,832 | 1,922 | .488 | -90 | 5 | 1 | 1 | 6 | 538 | 2 | 17,042 | 128,379 | 32,850 | 3,968 | .256 | 17,328 | 4.25 |
| 2 | Atlanta Braves | 1876 | 2021 | 21,697 | 10,801 | 10,742 | .501 | 59 | 20 | 17 | 3 | 26 | 2052 | 53 | 96,717 | 742,943 | 193,031 | 14,187 | .260 | 95,758 | 3.67 |
| | Also played as Milwaukee Braves, Boston Braves, Boston Bees, Boston Rustlers, Boston Doves, Boston Beaneaters and Boston Red Stockings |
| 3 | Baltimore Orioles | 1901 | 2021 | 18,793 | 8,833 | 9,850 | .473 | -1017 | 9 | 7 | 3 | 14 | 1899 | 34 | 81,015 | 638,453 | 165,005 | 13,749 | .258 | 86,525 | 4.05 |
| | Also played as St. Louis Browns and Milwaukee Brewers |
| | Boston Braves, see Atlanta Braves |
| 4 | Boston Red Sox | 1901 | 2021 | 18,783 | 9,700 | 9,000 | .519 | 700 | 10 | 14 | 9 | 24 | 1856 | 37 | 87,713 | 642,785 | 171,724 | 13,963 | .267 | 84,095 | 3.91 |
| | Also played as Boston Americans |
| | Brooklyn Dodgers, see Los Angeles Dodgers |
| | California Angels, see Los Angeles Angels |
| 5 | Chicago Cubs | 1876 | 2021 | 21,737 | 11,072 | 10,504 | .513 | 568 | 8 | 17 | 3 | 21 | 2153 | 45 | 100,064 | 744,138 | 195,173 | 14,613 | .262 | 96,598 | 3.69 |
| | Also played as Chicago Orphans, Chicago Colts and Chicago White Stockings |
| 6 | Chicago White Sox | 1901 | 2021 | 18,791 | 9,393 | 9,295 | .503 | 98 | 5 | 6 | 3 | 10 | 1820 | 32 | 81,943 | 636,347 | 165,626 | 11,760 | .260 | 81,528 | 3.78 |
| 7 | Cincinnati Reds | 1882 | 2021 | 21,321 | 10,701 | 10,481 | .505 | 220 | 10 | 10 | 5 | 16 | 2057 | 36 | 95,736 | 726,896 | 189,793 | 13,703 | .261 | 94,783 | 3.75 |
| | Also played as Cincinnati Redlegs and Cincinnati Red Stockings |
| 8 | Cleveland Indians | 1901 | 2021 | 18,791 | 9,575 | 9,125 | .512 | 450 | 10 | 6 | 2 | 15 | 1939 | 34 | 85,105 | 640,734 | 169,970 | 13,391 | .265 | 82,988 | 3.83 |
| | Also played as Cleveland Naps, Cleveland Bronchos and Cleveland Blues |
| 9 | Colorado Rockies | 1993 | 2021 | 4,501 | 2,118 | 2,383 | .471 | -265 | 0 | 1 | 0 | 5 | 605 | 1 | 22,657 | 154,856 | 42,306 | 5,155 | .273 | 23,726 | 4.97 |
| 10 | Detroit Tigers | 1901 | 2021 | 18,817 | 9,431 | 9,293 | .504 | 138 | 7 | 11 | 4 | 16 | 1736 | 24 | 86,723 | 642,012 | 170,152 | 14,047 | .265 | 86,303 | 4.00 |
| 11 | Houston Astros | 1962 | 2021 | 9,460 | 4,706 | 4,749 | .498 | -43 | 10 | 3 | 1 | 14 | 947 | 10 | 40,087 | 320,992 | 81,801 | 7,700 | .255 | 39,841 | 3.81 |
| | Also played as Houston Colt .45s |
| | Kansas City Athletics, see Oakland Athletics |
| 12 | Kansas City Royals | 1969 | 2021 | 8,313 | 3,985 | 4,326 | .479 | -341 | 8 | 4 | 2 | 9 | 935 | 4 | 36,470 | 284,725 | 75,083 | 6,468 | .264 | 38,354 | 4.24 |
| 13 | Los Angeles Angels | 1961 | 2021 | 9,621 | 4,798 | 4,820 | .499 | -22 | 9 | 1 | 1 | 10 | 1133 | 12 | 41,750 | 326,717 | 83,995 | 8,530 | .257 | 42,102 | 3.99 |
| | Also played as Los Angeles Angels of Anaheim, Anaheim Angels and California Angels |
| 14 | Los Angeles Dodgers | 1884 | 2021 | 21,120 | 11,098 | 9,883 | .529 | 1215 | 19 | 25 | 7 | 34 | 1893 | 50 | 94,887 | 719,675 | 188,108 | 13,304 | .261 | 89,459 | 3.53 |
| | Also played as Brooklyn Dodgers, Brooklyn Robins, Brooklyn Superbas, Brooklyn Bridegrooms, Brooklyn Grooms, Brooklyn Grays and Brooklyn Atlantics |
| 15 | Miami Marlins | 1993 | 2021 | 4,493 | 2,074 | 2,419 | .462 | -345 | 0 | 2 | 2 | 3 | 659 | 5 | 19,091 | 152,883 | 39,168 | 4,072 | .256 | 20,863 | 4.30 |
| | Also played as Florida Marlins |
| | Milwaukee Braves, see Atlanta Braves |
| 16 | Milwaukee Brewers | 1969 | 2021 | 8,323 | 4,020 | 4,299 | .483 | -279 | 4 | 1 | 0 | 7 | 960 | 7 | 36,933 | 282,802 | 72,718 | 8,068 | .257 | 37,999 | 4.17 |
| | Also played as Seattle Pilots |
| | Milwaukee Brewers (1901), see Baltimore Orioles |
| 17 | Minnesota Twins | 1901 | 2021 | 18,803 | 8,995 | 9,699 | .481 | -704 | 12 | 6 | 3 | 17 | 1743 | 25 | 82,626 | 641,648 | 168,596 | 11,332 | .263 | 86,009 | 3.99 |
| | Also played as Washington Senators |
| | Montreal Expos, see Washington Nationals |
| | New York Giants, see San Francisco Giants |
| 18 | New York Mets | 1962 | 2021 | 9,452 | 4,535 | 4,909 | .480 | -374 | 6 | 5 | 2 | 9 | 1152 | 15 | 38,707 | 319,920 | 79,970 | 7,889 | .250 | 39,764 | 3.80 |
| 19 | New York Yankees | 1903 | 2021 | 18,494 | 10,487 | 7,919 | .570 | 2568 | 19 | 40 | 27 | 56 | 1735 | 46 | 89,917 | 630,761 | 167,929 | 16,475 | .266 | 77,217 | 3.65 |
| | Also played as New York Highlanders |
| 20 | Oakland Athletics | 1901 | 2021 | 18,756 | 9,134 | 9,535 | .489 | -401 | 17 | 15 | 9 | 29 | 2005 | 41 | 83,133 | 636,147 | 164,296 | 13,538 | .258 | 85,480 | 3.98 |
| | Also played as Kansas City Athletics and Philadelphia Athletics |
| | Philadelphia Athletics, see Oakland Athletics |
| 21 | Philadelphia Phillies | 1883 | 2021 | 21,128 | 9,917 | 11,096 | .472 | -1179 | 12 | 7 | 2 | 14 | 2122 | 35 | 93,627 | 723,020 | 188,369 | 13,473 | .261 | 99,644 | 3.99 |
| | Also played as Philadelphia Quakers |
| 22 | Pittsburgh Pirates | 1882 | 2021 | 21,279 | 10,611 | 10,528 | .502 | 83 | 9 | 9 | 5 | 17 | 2042 | 40 | 94,929 | 729,422 | 192,578 | 11,718 | .264 | 94,693 | 3.74 |
| | Also played as Pittsburgh Alleghenys |
| 23 | San Diego Padres | 1969 | 2021 | 8,328 | 3,853 | 4,473 | .463 | -620 | 5 | 2 | 0 | 6 | 1075 | 12 | 33,501 | 281,608 | 70,218 | 6,641 | .249 | 36,557 | 3.97 |
| 24 | San Francisco Giants | 1883 | 2021 | 21,203 | 11,277 | 9,763 | .536 | 1514 | 8 | 23 | 8 | 26 | 1857 | 57 | 98,189 | 724,014 | 190,924 | 14,958 | .264 | 90,774 | 3.58 |
| | Also played as New York Giants and New York Gothams |
| 25 | Seattle Mariners | 1977 | 2021 | 7,032 | 3,315 | 3,715 | .472 | -400 | 3 | 0 | 0 | 4 | 925 | 6 | 31,241 | 240,271 | 62,190 | 7,035 | .259 | 33,143 | 4.34 |
| | Seattle Pilots, see Milwaukee Brewers |
| | St. Louis Browns, see Baltimore Orioles |
| 26 | St. Louis Cardinals | 1882 | 2021 | 21,318 | 11,013 | 10,153 | .520 | 860 | 14 | 23 | 11 | 30 | 2160 | 47 | 97,764 | 730,969 | 194,444 | 12,489 | .266 | 93,861 | 3.68 |
| | Also played as St. Louis Perfectos, St. Louis Browns and St. Louis Brown Stockings |
| 27 | Tampa Bay Rays | 1998 | 2021 | 3,750 | 1,806 | 1,944 | .482 | -138 | 3 | 2 | 0 | 6 | 538 | 1 | 16,679 | 127,740 | 32,597 | 3,886 | .255 | 17,389 | 4.30 |
| | Also played as Tampa Bay Devil Rays |
| 28 | Texas Rangers | 1961 | 2021 | 9,606 | 4,566 | 5,034 | .476 | -468 | 7 | 2 | 0 | 8 | 1192 | 8 | 43,202 | 328,071 | 84,864 | 9,511 | .259 | 45,322 | 4.29 |
| | Also played as Washington Senators |
| 29 | Toronto Blue Jays | 1977 | 2021 | 7,031 | 3,481 | 3,547 | .495 | -66 | 6 | 2 | 2 | 8 | 869 | 8 | 32,538 | 241,048 | 62,788 | 7,599 | .260 | 32,322 | 4.24 |
| 30 | Washington Nationals | 1969 | 2021 | 8,317 | 4,058 | 4,255 | .488 | -197 | 5 | 1 | 1 | 6 | 983 | 10 | 34,893 | 281,400 | 71,502 | 7,094 | .254 | 35,775 | 3.89 |
| | Also played as Montreal Expos |
| | Washington Senators (1901-1960), see Minnesota Twins |
| | Washington Senators (1961-1971), see Texas Rangers |
Inactive Franchises