List of Philadelphia Union seasons
Since its foundation in 2008, the American soccer club Philadelphia Union has played in Major League Soccer. The team has finished as runner-ups thrice in the U.S. Open Cup and once in the MLS Cup. The following is a list of seasons completed by the club, inclusive of all competitive competitions.
Key
;Key to competitions- Major League Soccer – The [United States Association football|soccer league system|top-flight] of soccer in the United States, established in 1996.
- U.S. Open Cup – The premier knockout cup competition in U.S. soccer, first contested in 1914.
- CONCACAF Champions Cup – The premier competition in North American soccer since 1962. It went by the name of Champions' Cup until 2008. It went by the name of CONCACAF Champions League from 2008 until 2023.
| 1st or W | Winners |
| 2nd or RU | Runners-up |
| 3rd | Third place |
| Last | Wooden Spoon |
| ♦ | MLS Golden Boot |
| Highest average attendance | |
| Italics | Ongoing competition |
;Key to cup record
- DNE = Did not enter
- DNQ = Did not qualify
- NH = Competition not held or canceled
- QR = Qualifying round
- PR = Preliminary round
- GS = Group stage
- R1 = First round
- R2 = Second round
- R3 = Third round
- R4 = Fourth round
- R5 = Fifth round
- Ro16 = Round of 16
- QF = Quarterfinals
- SF = Semifinals
- F = Final
- RU = Runners-up
- W = Winners