| | Anaheim Angels, see Los Angeles Angels |
| 1 | Arizona Diamondbacks | 1998 | 2021 | 3,712 | 1,813 | 1,899 | .488 | -86 | 5 | 1 | 1 | 6 | 528 | 2 | 16,860 | 126,963 | 32,497 | 3,928 | .256 | 17,099 | 4.24 |
| 2 | Atlanta Braves | 1876 | 2021 | 21,656 | 10,774 | 10,728 | .501 | 46 | 20 | 17 | 3 | 26 | 2048 | 53 | 96,501 | 741,547 | 192,682 | 14,122 | .260 | 95,614 | 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 | 18,752 | 8,821 | 9,821 | .473 | -1000 | 9 | 7 | 3 | 14 | 1891 | 34 | 80,850 | 637,068 | 164,667 | 13,693 | .258 | 86,254 | 4.04 |
| | Also played as St. Louis Browns and Milwaukee Brewers |
| | Boston Braves, see Atlanta Braves |
| 4 | Boston Red Sox | 1901 | 2021 | 18,741 | 9,680 | 8,978 | .519 | 702 | 10 | 14 | 9 | 24 | 1852 | 37 | 87,501 | 641,391 | 171,361 | 13,903 | .267 | 83,885 | 3.91 |
| | Also played as Boston Americans |
| | Brooklyn Dodgers, see Los Angeles Dodgers |
| | California Angels, see Los Angeles Angels |
| 5 | Chicago Cubs | 1876 | 2021 | 21,694 | 11,059 | 10,474 | .514 | 585 | 8 | 17 | 3 | 21 | 2142 | 45 | 99,881 | 742,709 | 194,831 | 14,562 | .262 | 96,326 | 3.68 |
| | Also played as Chicago Orphans, Chicago Colts and Chicago White Stockings |
| 6 | Chicago White Sox | 1901 | 2021 | 18,747 | 9,369 | 9,275 | .503 | 94 | 5 | 6 | 3 | 10 | 1816 | 32 | 81,721 | 634,855 | 165,252 | 11,692 | .260 | 81,341 | 3.78 |
| 7 | Cincinnati Reds | 1882 | 2021 | 21,277 | 10,675 | 10,463 | .505 | 212 | 10 | 10 | 5 | 16 | 2053 | 36 | 95,506 | 725,409 | 189,415 | 13,633 | .261 | 94,591 | 3.75 |
| | Also played as Cincinnati Redlegs and Cincinnati Red Stockings |
| 8 | Cleveland Indians | 1901 | 2021 | 18,749 | 9,554 | 9,104 | .512 | 450 | 10 | 6 | 2 | 15 | 1935 | 34 | 84,902 | 639,302 | 169,602 | 13,328 | .265 | 82,798 | 3.83 |
| | Also played as Cleveland Naps, Cleveland Bronchos and Cleveland Blues |
| 9 | Colorado Rockies | 1993 | 2021 | 4,460 | 2,096 | 2,364 | .470 | -268 | 0 | 1 | 0 | 5 | 603 | 1 | 22,444 | 153,469 | 41,942 | 5,095 | .273 | 23,534 | 4.98 |
| 10 | Detroit Tigers | 1901 | 2021 | 18,775 | 9,409 | 9,273 | .504 | 136 | 7 | 11 | 4 | 16 | 1733 | 24 | 86,525 | 640,605 | 169,799 | 13,998 | .265 | 86,112 | 4.00 |
| 11 | Houston Astros | 1962 | 2021 | 9,419 | 4,684 | 4,730 | .498 | -46 | 10 | 3 | 1 | 14 | 939 | 10 | 39,886 | 319,578 | 81,437 | 7,647 | .255 | 39,683 | 3.81 |
| | Also played as Houston Colt .45s |
| | Kansas City Athletics, see Oakland Athletics |
| 12 | Kansas City Royals | 1969 | 2021 | 8,271 | 3,963 | 4,306 | .479 | -343 | 8 | 4 | 2 | 9 | 933 | 4 | 36,289 | 283,305 | 74,732 | 6,422 | .264 | 38,169 | 4.25 |
| 13 | Los Angeles Angels | 1961 | 2021 | 9,577 | 4,779 | 4,795 | .499 | -16 | 9 | 1 | 1 | 10 | 1123 | 12 | 41,589 | 325,246 | 83,656 | 8,493 | .257 | 41,895 | 3.99 |
| | Also played as Los Angeles Angels of Anaheim, Anaheim Angels and California Angels |
| 14 | Los Angeles Dodgers | 1884 | 2021 | 21,078 | 11,070 | 9,869 | .529 | 1201 | 19 | 25 | 7 | 34 | 1879 | 50 | 94,663 | 718,207 | 187,741 | 13,236 | .261 | 89,330 | 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 | 4,449 | 2,059 | 2,390 | .463 | -331 | 0 | 2 | 2 | 3 | 649 | 5 | 18,921 | 151,421 | 38,814 | 4,031 | .256 | 20,626 | 4.30 |
| | Also played as Florida Marlins |
| | Milwaukee Braves, see Atlanta Braves |
| 16 | Milwaukee Brewers | 1969 | 2021 | 8,282 | 3,994 | 4,284 | .482 | -290 | 4 | 1 | 0 | 7 | 954 | 7 | 36,722 | 281,415 | 72,354 | 8,017 | .257 | 37,856 | 4.17 |
| | Also played as Seattle Pilots |
| | Milwaukee Brewers (1901), see Baltimore Orioles |
| 17 | Minnesota Twins | 1901 | 2021 | 18,760 | 8,974 | 9,677 | .481 | -703 | 12 | 6 | 3 | 17 | 1736 | 25 | 82,427 | 640,211 | 168,254 | 11,271 | .263 | 85,782 | 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 | 9,407 | 4,519 | 4,880 | .481 | -361 | 6 | 5 | 2 | 9 | 1141 | 15 | 38,536 | 318,436 | 79,611 | 7,837 | .250 | 39,555 | 3.79 |
| 19 | New York Yankees | 1903 | 2021 | 18,451 | 10,455 | 7,908 | .569 | 2547 | 19 | 40 | 27 | 56 | 1719 | 46 | 89,713 | 629,349 | 167,590 | 16,420 | .266 | 77,067 | 3.65 |
| | Also played as New York Highlanders |
| 20 | Oakland Athletics | 1901 | 2021 | 18,715 | 9,113 | 9,515 | .489 | -402 | 17 | 15 | 9 | 29 | 2000 | 41 | 82,952 | 634,760 | 163,964 | 13,485 | .258 | 85,332 | 3.98 |
| | Also played as Kansas City Athletics and Philadelphia Athletics |
| | Philadelphia Athletics, see Oakland Athletics |
| 21 | Philadelphia Phillies | 1883 | 2021 | 21,084 | 9,894 | 11,075 | .472 | -1181 | 12 | 7 | 2 | 14 | 2117 | 35 | 93,428 | 721,581 | 188,032 | 13,416 | .261 | 99,439 | 3.99 |
| | Also played as Philadelphia Quakers |
| 22 | Pittsburgh Pirates | 1882 | 2021 | 21,236 | 10,596 | 10,500 | .502 | 96 | 9 | 9 | 5 | 17 | 2035 | 40 | 94,764 | 728,006 | 192,235 | 11,685 | .264 | 94,458 | 3.74 |
| | Also played as Pittsburgh Alleghenys |
| 23 | San Diego Padres | 1969 | 2021 | 8,287 | 3,835 | 4,450 | .463 | -615 | 5 | 2 | 0 | 6 | 1069 | 12 | 33,314 | 280,230 | 69,886 | 6,598 | .249 | 36,369 | 3.96 |
| 24 | San Francisco Giants | 1883 | 2021 | 21,161 | 11,248 | 9,750 | .536 | 1498 | 8 | 23 | 8 | 26 | 1854 | 57 | 97,990 | 722,577 | 190,564 | 14,890 | .264 | 90,620 | 3.58 |
| | Also played as New York Giants and New York Gothams |
| 25 | Seattle Mariners | 1977 | 2021 | 6,990 | 3,291 | 3,697 | .471 | -406 | 3 | 0 | 0 | 4 | 917 | 6 | 31,054 | 238,842 | 61,855 | 6,980 | .259 | 32,951 | 4.34 |
| | Seattle Pilots, see Milwaukee Brewers |
| | St. Louis Browns, see Baltimore Orioles |
| 26 | St. Louis Cardinals | 1882 | 2021 | 21,279 | 10,991 | 10,136 | .520 | 855 | 14 | 23 | 11 | 30 | 2156 | 47 | 97,593 | 729,647 | 194,104 | 12,440 | .266 | 93,705 | 3.68 |
| | Also played as St. Louis Perfectos, St. Louis Browns and St. Louis Brown Stockings |
| 27 | Tampa Bay Rays | 1998 | 2021 | 3,709 | 1,777 | 1,932 | .479 | -155 | 3 | 2 | 0 | 6 | 528 | 1 | 16,426 | 126,330 | 32,239 | 3,820 | .255 | 17,216 | 4.30 |
| | Also played as Tampa Bay Devil Rays |
| 28 | Texas Rangers | 1961 | 2021 | 9,565 | 4,556 | 5,003 | .477 | -447 | 7 | 2 | 0 | 8 | 1181 | 8 | 43,075 | 326,722 | 84,577 | 9,478 | .259 | 45,094 | 4.28 |
| | Also played as Washington Senators |
| 29 | Toronto Blue Jays | 1977 | 2021 | 6,988 | 3,459 | 3,526 | .495 | -67 | 6 | 2 | 2 | 8 | 861 | 8 | 32,339 | 239,650 | 62,433 | 7,538 | .261 | 32,156 | 4.24 |
| 30 | Washington Nationals | 1969 | 2021 | 8,275 | 4,045 | 4,226 | .489 | -181 | 5 | 1 | 1 | 6 | 974 | 10 | 34,689 | 280,000 | 71,128 | 7,046 | .254 | 35,525 | 3.89 |
| | Also played as Montreal Expos |
| | Washington Senators (1901-1960), see Minnesota Twins |
| | Washington Senators (1961-1971), see Texas Rangers |
Inactive Franchises