| | Anaheim Angels, see Los Angeles Angels |
| 1 | Arizona Diamondbacks | 1998 | 2021 | 3,780 | 1,838 | 1,942 | .486 | -104 | 5 | 1 | 1 | 6 | 542 | 2 | 17,140 | 129,252 | 33,043 | 3,990 | .256 | 17,474 | 4.26 |
| 2 | Atlanta Braves | 1876 | 2021 | 21,725 | 10,815 | 10,756 | .501 | 59 | 20 | 17 | 3 | 26 | 2053 | 53 | 96,857 | 743,909 | 193,272 | 14,235 | .260 | 95,865 | 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 | 18,822 | 8,843 | 9,869 | .473 | -1026 | 9 | 7 | 3 | 14 | 1906 | 34 | 81,135 | 639,421 | 165,233 | 13,785 | .258 | 86,697 | 4.05 |
| | Also played as St. Louis Browns and Milwaukee Brewers |
| | Boston Braves, see Atlanta Braves |
| 4 | Boston Red Sox | 1901 | 2021 | 18,809 | 9,714 | 9,012 | .519 | 702 | 10 | 14 | 9 | 24 | 1866 | 37 | 87,857 | 643,698 | 171,977 | 14,001 | .267 | 84,228 | 3.91 |
| | Also played as Boston Americans |
| | Brooklyn Dodgers, see Los Angeles Dodgers |
| | California Angels, see Los Angeles Angels |
| 5 | Chicago Cubs | 1876 | 2021 | 21,763 | 11,083 | 10,519 | .513 | 564 | 8 | 17 | 3 | 21 | 2156 | 45 | 100,188 | 745,000 | 195,391 | 14,654 | .262 | 96,761 | 3.69 |
| | Also played as Chicago Orphans, Chicago Colts and Chicago White Stockings |
| 6 | Chicago White Sox | 1901 | 2021 | 18,817 | 9,406 | 9,308 | .503 | 98 | 5 | 6 | 3 | 10 | 1821 | 32 | 82,052 | 637,211 | 165,853 | 11,785 | .260 | 81,628 | 3.78 |
| 7 | Cincinnati Reds | 1882 | 2021 | 21,347 | 10,711 | 10,497 | .505 | 214 | 10 | 10 | 5 | 16 | 2061 | 36 | 95,840 | 727,737 | 189,994 | 13,734 | .261 | 94,899 | 3.75 |
| | Also played as Cincinnati Redlegs and Cincinnati Red Stockings |
| 8 | Cleveland Indians | 1901 | 2021 | 18,820 | 9,588 | 9,141 | .512 | 447 | 10 | 6 | 2 | 15 | 1940 | 34 | 85,223 | 641,671 | 170,193 | 13,426 | .265 | 83,108 | 3.83 |
| | Also played as Cleveland Naps, Cleveland Bronchos and Cleveland Blues |
| 9 | Colorado Rockies | 1993 | 2021 | 4,528 | 2,130 | 2,398 | .470 | -268 | 0 | 1 | 0 | 5 | 609 | 1 | 22,778 | 155,773 | 42,522 | 5,189 | .273 | 23,866 | 4.97 |
| 10 | Detroit Tigers | 1901 | 2021 | 18,843 | 9,444 | 9,306 | .504 | 138 | 7 | 11 | 4 | 16 | 1737 | 24 | 86,831 | 642,888 | 170,364 | 14,078 | .265 | 86,403 | 4.00 |
| 11 | Houston Astros | 1962 | 2021 | 9,488 | 4,721 | 4,762 | .498 | -41 | 10 | 3 | 1 | 14 | 949 | 10 | 40,232 | 321,977 | 82,063 | 7,743 | .255 | 39,965 | 3.81 |
| | Also played as Houston Colt .45s |
| | Kansas City Athletics, see Oakland Athletics |
| 12 | Kansas City Royals | 1969 | 2021 | 8,340 | 3,998 | 4,340 | .479 | -342 | 8 | 4 | 2 | 9 | 937 | 4 | 36,588 | 285,649 | 75,325 | 6,497 | .264 | 38,477 | 4.24 |
| 13 | Los Angeles Angels | 1961 | 2021 | 9,647 | 4,809 | 4,835 | .499 | -26 | 9 | 1 | 1 | 10 | 1139 | 12 | 41,859 | 327,570 | 84,187 | 8,558 | .257 | 42,224 | 3.99 |
| | Also played as Los Angeles Angels of Anaheim, Anaheim Angels and California Angels |
| 14 | Los Angeles Dodgers | 1884 | 2021 | 21,147 | 11,117 | 9,891 | .529 | 1226 | 19 | 25 | 7 | 34 | 1894 | 50 | 95,007 | 720,551 | 188,316 | 13,342 | .261 | 89,543 | 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 | 4,519 | 2,085 | 2,434 | .461 | -349 | 0 | 2 | 2 | 3 | 662 | 5 | 19,186 | 153,738 | 39,359 | 4,099 | .256 | 20,980 | 4.30 |
| | Also played as Florida Marlins |
| | Milwaukee Braves, see Atlanta Braves |
| 16 | Milwaukee Brewers | 1969 | 2021 | 8,350 | 4,036 | 4,310 | .484 | -274 | 4 | 1 | 0 | 7 | 960 | 7 | 37,054 | 283,693 | 72,924 | 8,099 | .257 | 38,107 | 4.16 |
| | Also played as Seattle Pilots |
| | Milwaukee Brewers (1901), see Baltimore Orioles |
| 17 | Minnesota Twins | 1901 | 2021 | 18,831 | 9,008 | 9,714 | .481 | -706 | 12 | 6 | 3 | 17 | 1746 | 25 | 82,733 | 642,567 | 168,805 | 11,367 | .263 | 86,128 | 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 | 9,479 | 4,547 | 4,924 | .480 | -377 | 6 | 5 | 2 | 9 | 1153 | 15 | 38,839 | 320,829 | 80,203 | 7,925 | .250 | 39,900 | 3.80 |
| 19 | New York Yankees | 1903 | 2021 | 18,522 | 10,500 | 7,934 | .570 | 2566 | 19 | 40 | 27 | 56 | 1735 | 46 | 90,042 | 631,686 | 168,150 | 16,522 | .266 | 77,353 | 3.65 |
| | Also played as New York Highlanders |
| 20 | Oakland Athletics | 1901 | 2021 | 18,783 | 9,149 | 9,547 | .489 | -398 | 17 | 15 | 9 | 29 | 2006 | 41 | 83,277 | 637,056 | 164,527 | 13,567 | .258 | 85,608 | 3.98 |
| | Also played as Kansas City Athletics and Philadelphia Athletics |
| | Philadelphia Athletics, see Oakland Athletics |
| 21 | Philadelphia Phillies | 1883 | 2021 | 21,156 | 9,934 | 11,107 | .472 | -1173 | 12 | 7 | 2 | 14 | 2124 | 35 | 93,773 | 723,968 | 188,619 | 13,513 | .261 | 99,768 | 3.99 |
| | Also played as Philadelphia Quakers |
| 22 | Pittsburgh Pirates | 1882 | 2021 | 21,305 | 10,622 | 10,543 | .502 | 79 | 9 | 9 | 5 | 17 | 2046 | 40 | 95,041 | 730,269 | 192,776 | 11,739 | .264 | 94,829 | 3.74 |
| | Also played as Pittsburgh Alleghenys |
| 23 | San Diego Padres | 1969 | 2021 | 8,354 | 3,862 | 4,490 | .462 | -628 | 5 | 2 | 0 | 6 | 1077 | 12 | 33,609 | 282,475 | 70,432 | 6,665 | .249 | 36,703 | 3.97 |
| 24 | San Francisco Giants | 1883 | 2021 | 21,231 | 11,296 | 9,772 | .536 | 1524 | 8 | 23 | 8 | 26 | 1859 | 57 | 98,343 | 724,988 | 191,184 | 15,000 | .264 | 90,882 | 3.57 |
| | Also played as New York Giants and New York Gothams |
| 25 | Seattle Mariners | 1977 | 2021 | 7,059 | 3,332 | 3,725 | .472 | -393 | 3 | 0 | 0 | 4 | 926 | 6 | 31,363 | 241,186 | 62,402 | 7,068 | .259 | 33,267 | 4.34 |
| | Seattle Pilots, see Milwaukee Brewers |
| | St. Louis Browns, see Baltimore Orioles |
| 26 | St. Louis Cardinals | 1882 | 2021 | 21,347 | 11,035 | 10,160 | .521 | 875 | 14 | 23 | 11 | 30 | 2160 | 47 | 97,931 | 731,943 | 194,708 | 12,539 | .266 | 93,968 | 3.68 |
| | Also played as St. Louis Perfectos, St. Louis Browns and St. Louis Brown Stockings |
| 27 | Tampa Bay Rays | 1998 | 2021 | 3,778 | 1,823 | 1,955 | .483 | -132 | 3 | 2 | 0 | 6 | 543 | 1 | 16,828 | 128,684 | 32,838 | 3,925 | .255 | 17,505 | 4.29 |
| | Also played as Tampa Bay Devil Rays |
| 28 | Texas Rangers | 1961 | 2021 | 9,634 | 4,579 | 5,049 | .476 | -470 | 7 | 2 | 0 | 8 | 1193 | 8 | 43,312 | 329,015 | 85,097 | 9,533 | .259 | 45,463 | 4.29 |
| | Also played as Washington Senators |
| 29 | Toronto Blue Jays | 1977 | 2021 | 7,060 | 3,502 | 3,555 | .496 | -53 | 6 | 2 | 2 | 8 | 872 | 8 | 32,709 | 242,040 | 63,060 | 7,658 | .261 | 32,433 | 4.23 |
| 30 | Washington Nationals | 1969 | 2021 | 8,346 | 4,067 | 4,275 | .488 | -208 | 5 | 1 | 1 | 6 | 987 | 10 | 35,036 | 282,414 | 71,766 | 7,130 | .254 | 35,952 | 3.90 |
| | Also played as Montreal Expos |
| | Washington Senators (1901-1960), see Minnesota Twins |
| | Washington Senators (1961-1971), see Texas Rangers |
Inactive Franchises