| Lou Sylvester | |
| Bats: | Right |
| Throws: | Right |
| Birth Date: | February 14, 1855 |
| Birth Place: | Springfield, Illinois |
| Death Place: | Brooklyn, New York |
| Debutleague: | MLB |
| Debutdate: | April 18 |
| Debutyear: | 1884 |
| Debutteam: | Cincinnati Outlaw Reds |
| Finalleague: | MLB |
| Finaldate: | August 14 |
| Finalyear: | 1887 |
| Finalteam: | St. Louis Browns |
| Statleague: | MLB |
| Stat1label: | Batting average |
| Stat1value: | .243 |
| Stat2label: | Hits |
| Stat2value: | 159 |
| Stat3label: | Runs |
| Stat3value: | 138 |
| Teams: |
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Louis J. Sylvester (February 14, 1855 – May 5, 1936), was a Major League Baseball player who played outfielder from -. He would play for the Cincinnati Outlaw Reds, Cincinnati Red Stockings, Louisville Colonels, and St. Louis Browns.