| | Anaheim Angels, see Los Angeles Angels |
| 1 | Arizona Diamondbacks | 1998 | 2021 | 3,747 | 1,829 | 1,918 | .488 | -89 | 5 | 1 | 1 | 6 | 536 | 2 | 17,006 | 128,128 | 32,788 | 3,957 | .256 | 17,293 | 4.25 |
| 2 | Atlanta Braves | 1876 | 2021 | 21,692 | 10,798 | 10,740 | .501 | 58 | 20 | 17 | 3 | 26 | 2052 | 53 | 96,698 | 742,778 | 192,992 | 14,181 | .260 | 95,738 | 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 | 18,787 | 8,831 | 9,846 | .473 | -1015 | 9 | 7 | 3 | 14 | 1897 | 34 | 80,976 | 638,238 | 164,941 | 13,736 | .258 | 86,490 | 4.05 |
| | Also played as St. Louis Browns and Milwaukee Brewers |
| | Boston Braves, see Atlanta Braves |
| 4 | Boston Red Sox | 1901 | 2021 | 18,777 | 9,696 | 8,998 | .519 | 698 | 10 | 14 | 9 | 24 | 1856 | 37 | 87,671 | 642,577 | 171,673 | 13,950 | .267 | 84,058 | 3.91 |
| | Also played as Boston Americans |
| | Brooklyn Dodgers, see Los Angeles Dodgers |
| | California Angels, see Los Angeles Angels |
| 5 | Chicago Cubs | 1876 | 2021 | 21,731 | 11,070 | 10,500 | .513 | 570 | 8 | 17 | 3 | 21 | 2153 | 45 | 100,027 | 743,941 | 195,126 | 14,603 | .262 | 96,549 | 3.69 |
| | Also played as Chicago Orphans, Chicago Colts and Chicago White Stockings |
| 6 | Chicago White Sox | 1901 | 2021 | 18,784 | 9,390 | 9,291 | .503 | 99 | 5 | 6 | 3 | 10 | 1820 | 32 | 81,905 | 636,096 | 165,553 | 11,752 | .260 | 81,484 | 3.78 |
| 7 | Cincinnati Reds | 1882 | 2021 | 21,315 | 10,697 | 10,479 | .505 | 218 | 10 | 10 | 5 | 16 | 2057 | 36 | 95,710 | 726,711 | 189,751 | 13,694 | .261 | 94,766 | 3.75 |
| | Also played as Cincinnati Redlegs and Cincinnati Red Stockings |
| 8 | Cleveland Indians | 1901 | 2021 | 18,785 | 9,571 | 9,123 | .512 | 448 | 10 | 6 | 2 | 15 | 1939 | 34 | 85,074 | 640,538 | 169,912 | 13,377 | .265 | 82,968 | 3.83 |
| | Also played as Cleveland Naps, Cleveland Bronchos and Cleveland Blues |
| 9 | Colorado Rockies | 1993 | 2021 | 4,495 | 2,115 | 2,380 | .471 | -265 | 0 | 1 | 0 | 5 | 605 | 1 | 22,625 | 154,664 | 42,262 | 5,146 | .273 | 23,693 | 4.97 |
| 10 | Detroit Tigers | 1901 | 2021 | 18,812 | 9,428 | 9,291 | .504 | 137 | 7 | 11 | 4 | 16 | 1736 | 24 | 86,710 | 641,839 | 170,112 | 14,043 | .265 | 86,290 | 4.00 |
| 11 | Houston Astros | 1962 | 2021 | 9,454 | 4,702 | 4,747 | .498 | -45 | 10 | 3 | 1 | 14 | 947 | 10 | 40,053 | 320,769 | 81,738 | 7,695 | .255 | 39,818 | 3.81 |
| | Also played as Houston Colt .45s |
| | Kansas City Athletics, see Oakland Athletics |
| 12 | Kansas City Royals | 1969 | 2021 | 8,306 | 3,980 | 4,324 | .479 | -344 | 8 | 4 | 2 | 9 | 935 | 4 | 36,431 | 284,464 | 75,009 | 6,462 | .264 | 38,329 | 4.25 |
| 13 | Los Angeles Angels | 1961 | 2021 | 9,615 | 4,797 | 4,815 | .499 | -18 | 9 | 1 | 1 | 10 | 1130 | 12 | 41,728 | 326,519 | 83,954 | 8,526 | .257 | 42,058 | 3.99 |
| | Also played as Los Angeles Angels of Anaheim, Anaheim Angels and California Angels |
| 14 | Los Angeles Dodgers | 1884 | 2021 | 21,114 | 11,094 | 9,881 | .529 | 1213 | 19 | 25 | 7 | 34 | 1891 | 50 | 94,865 | 719,462 | 188,068 | 13,295 | .261 | 89,440 | 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 | 4,487 | 2,072 | 2,415 | .462 | -343 | 0 | 2 | 2 | 3 | 658 | 5 | 19,074 | 152,694 | 39,126 | 4,069 | .256 | 20,834 | 4.30 |
| | Also played as Florida Marlins |
| | Milwaukee Braves, see Atlanta Braves |
| 16 | Milwaukee Brewers | 1969 | 2021 | 8,317 | 4,016 | 4,297 | .483 | -281 | 4 | 1 | 0 | 7 | 960 | 7 | 36,905 | 282,617 | 72,672 | 8,062 | .257 | 37,978 | 4.17 |
| | Also played as Seattle Pilots |
| | Milwaukee Brewers (1901), see Baltimore Orioles |
| 17 | Minnesota Twins | 1901 | 2021 | 18,798 | 8,993 | 9,696 | .481 | -703 | 12 | 6 | 3 | 17 | 1743 | 25 | 82,603 | 641,475 | 168,555 | 11,323 | .263 | 85,973 | 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 | 9,446 | 4,534 | 4,904 | .480 | -370 | 6 | 5 | 2 | 9 | 1151 | 15 | 38,692 | 319,722 | 79,925 | 7,884 | .250 | 39,742 | 3.80 |
| 19 | New York Yankees | 1903 | 2021 | 18,489 | 10,482 | 7,919 | .570 | 2563 | 19 | 40 | 27 | 56 | 1735 | 46 | 89,885 | 630,585 | 167,885 | 16,463 | .266 | 77,203 | 3.65 |
| | Also played as New York Highlanders |
| 20 | Oakland Athletics | 1901 | 2021 | 18,750 | 9,134 | 9,529 | .489 | -395 | 17 | 15 | 9 | 29 | 2005 | 41 | 83,115 | 635,945 | 164,250 | 13,533 | .258 | 85,447 | 3.98 |
| | Also played as Kansas City Athletics and Philadelphia Athletics |
| | Philadelphia Athletics, see Oakland Athletics |
| 21 | Philadelphia Phillies | 1883 | 2021 | 21,122 | 9,915 | 11,092 | .472 | -1177 | 12 | 7 | 2 | 14 | 2122 | 35 | 93,598 | 722,810 | 188,323 | 13,463 | .261 | 99,612 | 3.99 |
| | Also played as Philadelphia Quakers |
| 22 | Pittsburgh Pirates | 1882 | 2021 | 21,272 | 10,607 | 10,525 | .502 | 82 | 9 | 9 | 5 | 17 | 2041 | 40 | 94,898 | 729,187 | 192,514 | 11,711 | .264 | 94,663 | 3.74 |
| | Also played as Pittsburgh Alleghenys |
| 23 | San Diego Padres | 1969 | 2021 | 8,322 | 3,851 | 4,469 | .463 | -618 | 5 | 2 | 0 | 6 | 1074 | 12 | 33,483 | 281,393 | 70,185 | 6,638 | .249 | 36,533 | 3.97 |
| 24 | San Francisco Giants | 1883 | 2021 | 21,197 | 11,272 | 9,762 | .536 | 1510 | 8 | 23 | 8 | 26 | 1857 | 57 | 98,162 | 723,811 | 190,878 | 14,945 | .264 | 90,758 | 3.58 |
| | Also played as New York Giants and New York Gothams |
| 25 | Seattle Mariners | 1977 | 2021 | 7,026 | 3,312 | 3,712 | .472 | -400 | 3 | 0 | 0 | 4 | 923 | 6 | 31,213 | 240,044 | 62,135 | 7,028 | .259 | 33,107 | 4.34 |
| | Seattle Pilots, see Milwaukee Brewers |
| | St. Louis Browns, see Baltimore Orioles |
| 26 | St. Louis Cardinals | 1882 | 2021 | 21,312 | 11,010 | 10,150 | .520 | 860 | 14 | 23 | 11 | 30 | 2160 | 47 | 97,740 | 730,770 | 194,398 | 12,483 | .266 | 93,836 | 3.68 |
| | Also played as St. Louis Perfectos, St. Louis Browns and St. Louis Brown Stockings |
| 27 | Tampa Bay Rays | 1998 | 2021 | 3,745 | 1,801 | 1,944 | .481 | -143 | 3 | 2 | 0 | 6 | 538 | 1 | 16,646 | 127,567 | 32,549 | 3,883 | .255 | 17,377 | 4.30 |
| | Also played as Tampa Bay Devil Rays |
| 28 | Texas Rangers | 1961 | 2021 | 9,600 | 4,564 | 5,030 | .476 | -466 | 7 | 2 | 0 | 8 | 1188 | 8 | 43,169 | 327,835 | 84,790 | 9,505 | .259 | 45,288 | 4.29 |
| | Also played as Washington Senators |
| 29 | Toronto Blue Jays | 1977 | 2021 | 7,024 | 3,478 | 3,543 | .495 | -65 | 6 | 2 | 2 | 8 | 869 | 8 | 32,517 | 240,810 | 62,733 | 7,594 | .261 | 32,298 | 4.24 |
| 30 | Washington Nationals | 1969 | 2021 | 8,311 | 4,056 | 4,251 | .488 | -195 | 5 | 1 | 1 | 6 | 982 | 10 | 34,869 | 281,189 | 71,447 | 7,087 | .254 | 35,746 | 3.89 |
| | Also played as Montreal Expos |
| | Washington Senators (1901-1960), see Minnesota Twins |
| | Washington Senators (1961-1971), see Texas Rangers |
Inactive Franchises