| | Anaheim Angels, see Los Angeles Angels |
| 1 | Arizona Diamondbacks | 1998 | 2021 | 3,786 | 1,840 | 1,946 | .486 | -106 | 5 | 1 | 1 | 6 | 542 | 2 | 17,171 | 129,462 | 33,101 | 3,995 | .256 | 17,501 | 4.26 |
| 2 | Atlanta Braves | 1876 | 2021 | 21,731 | 10,820 | 10,757 | .501 | 63 | 21 | 18 | 4 | 27 | 2055 | 53 | 96,885 | 744,097 | 193,317 | 14,242 | .260 | 95,880 | 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 | 18,828 | 8,845 | 9,873 | .473 | -1028 | 9 | 7 | 3 | 14 | 1906 | 34 | 81,154 | 639,617 | 165,279 | 13,790 | .258 | 86,735 | 4.05 |
| | Also played as St. Louis Browns and Milwaukee Brewers |
| | Boston Braves, see Atlanta Braves |
| 4 | Boston Red Sox | 1901 | 2021 | 18,815 | 9,718 | 9,014 | .519 | 704 | 10 | 14 | 9 | 25 | 1866 | 37 | 87,883 | 643,901 | 172,025 | 14,012 | .267 | 84,248 | 3.91 |
| | Also played as Boston Americans |
| | Brooklyn Dodgers, see Los Angeles Dodgers |
| | California Angels, see Los Angeles Angels |
| 5 | Chicago Cubs | 1876 | 2021 | 21,769 | 11,087 | 10,521 | .513 | 566 | 8 | 17 | 3 | 21 | 2161 | 45 | 100,218 | 745,201 | 195,449 | 14,659 | .262 | 96,782 | 3.69 |
| | Also played as Chicago Orphans, Chicago Colts and Chicago White Stockings |
| 6 | Chicago White Sox | 1901 | 2021 | 18,823 | 9,411 | 9,309 | .503 | 102 | 6 | 6 | 3 | 11 | 1821 | 34 | 82,088 | 637,409 | 165,910 | 11,796 | .260 | 81,647 | 3.78 |
| 7 | Cincinnati Reds | 1882 | 2021 | 21,353 | 10,713 | 10,501 | .505 | 212 | 10 | 10 | 5 | 16 | 2063 | 36 | 95,869 | 727,939 | 190,044 | 13,744 | .261 | 94,933 | 3.75 |
| | Also played as Cincinnati Redlegs and Cincinnati Red Stockings |
| 8 | Cleveland Guardians | 1901 | 2021 | 18,827 | 9,592 | 9,144 | .512 | 448 | 10 | 6 | 2 | 15 | 1940 | 35 | 85,263 | 641,912 | 170,255 | 13,431 | .265 | 83,141 | 3.83 |
| | Also played as Cleveland Indians, Cleveland Naps, Cleveland Bronchos and Cleveland Blues |
| 9 | Colorado Rockies | 1993 | 2021 | 4,534 | 2,133 | 2,401 | .470 | -268 | 0 | 1 | 0 | 5 | 609 | 1 | 22,810 | 155,980 | 42,581 | 5,195 | .273 | 23,900 | 4.98 |
| 10 | Detroit Tigers | 1901 | 2021 | 18,850 | 9,446 | 9,311 | .504 | 135 | 7 | 11 | 4 | 16 | 1737 | 24 | 86,862 | 643,128 | 170,425 | 14,083 | .265 | 86,441 | 4.00 |
| 11 | Houston Astros | 1962 | 2021 | 9,494 | 4,725 | 4,764 | .498 | -39 | 11 | 4 | 1 | 15 | 949 | 10 | 40,262 | 322,180 | 82,117 | 7,755 | .255 | 39,995 | 3.81 |
| | Also played as Houston Colt .45s |
| | Kansas City Athletics, see Oakland Athletics |
| 12 | Kansas City Royals | 1969 | 2021 | 8,347 | 4,001 | 4,344 | .479 | -343 | 8 | 4 | 2 | 9 | 938 | 4 | 36,622 | 285,881 | 75,386 | 6,501 | .264 | 38,517 | 4.25 |
| 13 | Los Angeles Angels | 1961 | 2021 | 9,653 | 4,812 | 4,838 | .499 | -26 | 9 | 1 | 1 | 10 | 1139 | 12 | 41,887 | 327,770 | 84,236 | 8,563 | .257 | 42,248 | 3.99 |
| | Also played as Los Angeles Angels of Anaheim, Anaheim Angels and California Angels |
| 14 | Los Angeles Dodgers | 1884 | 2021 | 21,153 | 11,123 | 9,891 | .529 | 1232 | 19 | 25 | 7 | 35 | 1894 | 51 | 95,054 | 720,746 | 188,374 | 13,361 | .261 | 89,568 | 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 | 4,526 | 2,088 | 2,438 | .461 | -350 | 0 | 2 | 2 | 3 | 662 | 5 | 19,203 | 153,943 | 39,400 | 4,104 | .256 | 21,011 | 4.30 |
| | Also played as Florida Marlins |
| | Milwaukee Braves, see Atlanta Braves |
| 16 | Milwaukee Brewers | 1969 | 2021 | 8,356 | 4,037 | 4,315 | .483 | -278 | 5 | 1 | 0 | 8 | 961 | 7 | 37,075 | 283,900 | 72,973 | 8,104 | .257 | 38,143 | 4.17 |
| | Also played as Seattle Pilots |
| | Milwaukee Brewers (1901), see Baltimore Orioles |
| 17 | Minnesota Twins | 1901 | 2021 | 18,837 | 9,012 | 9,716 | .481 | -704 | 12 | 6 | 3 | 17 | 1746 | 27 | 82,765 | 642,769 | 168,860 | 11,377 | .263 | 86,156 | 4.00 |
| | Also played as Washington Senators |
| | Montreal Expos, see Washington Nationals |
| | New York Giants, see San Francisco Giants |
| 18 | New York Mets | 1962 | 2021 | 9,486 | 4,551 | 4,927 | .480 | -376 | 6 | 5 | 2 | 9 | 1153 | 16 | 38,869 | 321,047 | 80,258 | 7,933 | .250 | 39,923 | 3.80 |
| 19 | New York Yankees | 1903 | 2021 | 18,528 | 10,503 | 7,937 | .570 | 2566 | 19 | 40 | 27 | 57 | 1735 | 47 | 90,066 | 631,883 | 168,191 | 16,531 | .266 | 77,379 | 3.65 |
| | Also played as New York Highlanders |
| 20 | Oakland Athletics | 1901 | 2021 | 18,789 | 9,150 | 9,552 | .489 | -402 | 17 | 15 | 9 | 29 | 2007 | 41 | 83,303 | 637,264 | 164,573 | 13,577 | .258 | 85,652 | 3.98 |
| | Also played as Kansas City Athletics and Philadelphia Athletics |
| | Philadelphia Athletics, see Oakland Athletics |
| 21 | Philadelphia Phillies | 1883 | 2021 | 21,162 | 9,935 | 11,112 | .472 | -1177 | 12 | 7 | 2 | 14 | 2125 | 36 | 93,789 | 724,161 | 188,655 | 13,519 | .261 | 99,790 | 3.99 |
| | Also played as Philadelphia Quakers |
| 22 | Pittsburgh Pirates | 1882 | 2021 | 21,312 | 10,625 | 10,547 | .502 | 78 | 9 | 9 | 5 | 17 | 2048 | 40 | 95,072 | 730,499 | 192,840 | 11,742 | .264 | 94,874 | 3.74 |
| | Also played as Pittsburgh Alleghenys |
| 23 | San Diego Padres | 1969 | 2021 | 8,360 | 3,863 | 4,495 | .462 | -632 | 5 | 2 | 0 | 6 | 1077 | 12 | 33,629 | 282,677 | 70,481 | 6,670 | .249 | 36,740 | 3.97 |
| 24 | San Francisco Giants | 1883 | 2021 | 21,237 | 11,301 | 9,773 | .536 | 1528 | 9 | 23 | 8 | 27 | 1859 | 57 | 98,371 | 725,180 | 191,231 | 15,004 | .264 | 90,897 | 3.57 |
| | Also played as New York Giants and New York Gothams |
| 25 | Seattle Mariners | 1977 | 2021 | 7,065 | 3,336 | 3,727 | .472 | -391 | 3 | 0 | 0 | 4 | 927 | 6 | 31,394 | 241,384 | 62,453 | 7,073 | .259 | 33,288 | 4.34 |
| | Seattle Pilots, see Milwaukee Brewers |
| | St. Louis Browns, see Baltimore Orioles |
| 26 | St. Louis Cardinals | 1882 | 2021 | 21,353 | 11,038 | 10,163 | .521 | 875 | 14 | 23 | 11 | 31 | 2160 | 49 | 97,952 | 732,122 | 194,750 | 12,548 | .266 | 93,989 | 3.68 |
| | Also played as St. Louis Perfectos, St. Louis Browns and St. Louis Brown Stockings |
| 27 | Tampa Bay Rays | 1998 | 2021 | 3,784 | 1,826 | 1,958 | .483 | -132 | 4 | 2 | 0 | 7 | 543 | 1 | 16,856 | 128,889 | 32,893 | 3,936 | .255 | 17,518 | 4.29 |
| | Also played as Tampa Bay Devil Rays |
| 28 | Texas Rangers | 1961 | 2021 | 9,640 | 4,582 | 5,052 | .476 | -470 | 7 | 2 | 0 | 8 | 1193 | 9 | 43,339 | 329,212 | 85,147 | 9,540 | .259 | 45,495 | 4.29 |
| | Also played as Washington Senators |
| 29 | Toronto Blue Jays | 1977 | 2021 | 7,066 | 3,506 | 3,557 | .496 | -51 | 6 | 2 | 2 | 8 | 872 | 8 | 32,747 | 242,248 | 63,121 | 7,672 | .261 | 32,460 | 4.23 |
| 30 | Washington Nationals | 1969 | 2021 | 8,352 | 4,068 | 4,280 | .487 | -212 | 5 | 1 | 1 | 6 | 988 | 10 | 35,057 | 282,613 | 71,814 | 7,133 | .254 | 35,985 | 3.90 |
| | Also played as Montreal Expos |
| | Washington Senators (1901-1960), see Minnesota Twins |
| | Washington Senators (1961-1971), see Texas Rangers |
Inactive Franchises