| Bill Harper | |
| Position: | Pitcher |
| Bats: | Switch |
| Throws: | Right |
| Birth Date: | June 14, 1889 |
| Birth Place: | Bertrand, Missouri |
| Death Place: | Somerville, Tennessee |
| Debutleague: | MLB |
| Debutdate: | June 10 |
| Debutyear: | 1911 |
| Debutteam: | St. Louis Browns |
| Finalleague: | MLB |
| Finaldate: | June 20 |
| Finalyear: | 1911 |
| Finalteam: | St. Louis Browns |
| Statleague: | MLB |
| Stat1label: | Win–loss record |
| Stat1value: | 0-0 |
| Stat2label: | Strikeouts |
| Stat2value: | 6 |
| Stat3label: | Earned run average |
| Stat3value: | 6.75 |
| Teams: |
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William Horner Harper (June 14, 1889 – June 17, 1951) was a Major League Baseball pitcher. He appeared in two games for the St. Louis Browns in .