PENNANTS WON SINCE SEATTLE JOINED MLB IN 1977
| Yankees | 9 |
| Braves | 5 |
| Cardinals | 5 |
| Dodgers | 4 |
| Athletics | 3 |
| Phillies | 3 |
| Red Sox | 3 |
| Blue Jays | 2 |
| Mets | 2 |
| Orioles | 2 |
| Royals | 2 |
| Indians | 2 |
| Twins | 2 |
| Tigers | 2 |
| Giants | 2 |
| Padres | 2 |
| Marlins | 2 |
| Astros | 1 |
| Pirates | 1 |
| Reds | 1 |
| Rockies | 1 |
| Rays | 1 |
| Angels | 1 |
| Brewers | 1 |
| Diamondbacks | 1 |
| White Sox | 1 |
| Expos/Nationals | 0 |
| Cubs* | 0 |
| Mariners | 0 |
| Nationals/Rangers | 0 |
* 10 Pennants won all time