| Bill Popp | |
| Position: | Pitcher |
| Bats: | Unknown |
| Throws: | Right |
| Birth Date: | 7 June 1877 |
| Birth Place: | St. Louis, Missouri |
| Death Place: | St. Louis, Missouri |
| Debutleague: | MLB |
| Debutdate: | April 19 |
| Debutyear: | 1902 |
| Debutteam: | St. Louis Cardinals |
| Finalleague: | MLB |
| Finaldate: | July 21 |
| Finalyear: | 1902 |
| Finalteam: | St. Louis Cardinals |
| Statleague: | MLB |
| Stat1label: | Win–loss record |
| Stat1value: | 2–6 |
| Stat2label: | Earned run average |
| Stat2value: | 4.92 |
| Stat3label: | Strikeouts |
| Stat3value: | 20 |
| Teams: | |
William Peter Popp (June 7, 1877 – September 5, 1909) was a Major League Baseball pitcher who played for the St. Louis Cardinals in 1902. He later was a manager in the minor leagues in 1904.