| Wally Mayer | |
| Position: | Catcher |
| Bats: | Right |
| Throws: | Right |
| Birth Date: | 8 July 1890 |
| Birth Place: | Cincinnati, Ohio |
| Death Place: | Minnetonka, Minnesota |
| Debutleague: | MLB |
| Debutdate: | September 28 |
| Debutyear: | 1911 |
| Debutteam: | Chicago White Sox |
| Finalleague: | MLB |
| Finaldate: | September 2 |
| Finalyear: | 1919 |
| Finalteam: | St. Louis Browns |
| Statleague: | MLB |
| Stat1label: | Batting average |
| Stat1value: | .193 |
| Stat2label: | Home runs |
| Stat2value: | 0 |
| Stat3label: | Runs batted in |
| Stat3value: | 20 |
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Walter A. Mayer (July 8, 1890 – November 18, 1951) was a backup catcher in Major League Baseball who played from through for the Chicago White Sox (1911–1912, 1914–1915), Boston Red Sox (1917–1918) and St. Louis Browns (1919). Listed at, 168 lb., Mayer batted and threw right-handed. He was born in Cincinnati.
In a seven-season career, Mayer was a .193 hitter (53-for-274) with 22 runs and 20 RBI in 132 games, including 14 doubles, one triple, one stolen base, and a .303 on-base percentage. He did not hit a home run. In 112 catching appearances, he committed 17 errors in 553 chances for a .968 fielding percentage.
Mayer died in Minnetonka, Minnesota at age 61.