Major Leaguers known to have died during the 1921 calendar year.
| Harry Arndt | 1879-02-12 | 1921-03-25 | 42.041 | IF | | 165 | R | R | 1879-02-12 | South Bend,IN | MLB | 1902-1907 | 1902-1907 | |
| Jimmy Barrett | 1875-03-28 | 1921-10-24 | 46.210 | OF | 5-7 | 170 | L | R | 1875-03-28 | Athol,MA | MLB | 1899-1908 | 1899-1908 | |
| George Bechtel | 1848-09-02 | 1921-04-03 | 72.213 | OF | 5-11 | 165 | | | 1848-09-02 | Philadelphia,PA | MLB | 1871-1876 | 1871-1876 | |
| Amos Booth | 1848-09-14 | 1921-07-01 | 72.290 | P | 5-9 | 159 | R | R | 1848-09-14 | Lebanon,OH | MLB | 1876-1882 | 1876-1882 | |
| Kid Butler | 0000-00-00 | 1921-04-09 | | OF | 5-6 | 140 | | | | Boston,MA | MLB | 1884-1884 | 1884-1884 | |
| Ed Carfrey | 1863-07-28 | 1921-10-02 | 58.066 | SS | | 0 | | | 1863-07-28 | Philadelphia,PA | MLB | 1890-1890 | 1890-1890 | |
| Jim Clinton | 1850-08-10 | 1921-09-03 | 71.024 | 3B | 5-8 | 174 | R | R | 1850-08-10 | New York,NY | MLB | 1872-1886 | 1872-1886 | |
| Pop Corkhill | 1858-04-11 | 1921-04-03 | 62.357 | OF | 5-10 | 180 | L | R | 1858-04-11 | Parkesburg,PA | MLB | 1883-1892 | 1883-1892 | |
| John Cullen | 1854-07-09 | 1921-02-11 | 66.217 | OF | 5-10 | 171 | | | 1854-07-09 | New Orleans,LA | MLB | 1884-1884 | 1884-1884 | |
| Jumbo Davis | 1861-09-05 | 1921-02-14 | 59.162 | 3B | 5-11 | 195 | L | R | 1861-09-05 | New York,NY | MLB | 1884-1891 | 1884-1891 | |
| Bill Dugan | 0000-00-00 | 1921-07-24 | | OF | | 0 | | | | New York,NY | MLB | 1884-1884 | 1884-1884 | |
| John Farrell | 1876-12-04 | 1921-05-13 | 44.160 | 2B | 5-10 | 160 | R | R | 1876-12-04 | Covington,KY | MLB | 1901-1905 | 1901-1905 | |
| Charles Fisher | 0000-00-00 | 1921-05-26 | | OF | | 0 | | | | Baltimore,MD | MLB | 1889-1889 | 1889-1889 | |
| John Fitzgerald | 1870-05-30 | 1921-03-31 | 50.305 | P | | 0 | | | 1870-05-30 | Natick,MA | MLB | 1891-1891 | 1891-1891 | |
| Robert Foster | 0000-00-00 | 1921-06-15 | | C | | 0 | | | | Philadelphia,PA | MLB | 1884-1884 | 1884-1884 | |
| Julie Freeman | 1868-11-07 | 1921-06-10 | 52.215 | P | | 0 | R | | 1868-11-07 | | MLB | 1888-1888 | 1888-1888 | |
| Emil Gross | 1858-03-03 | 1921-08-24 | 63.174 | C | 6-0 | 190 | R | R | 1858-03-03 | Chicago,IL | MLB | 1879-1884 | 1879-1884 | |
| Charlie Hall | 1863-08-24 | 1921-06-23 | 57.303 | OF | 5-10 | 158 | L | | 1863-08-24 | Toulon,IL | MLB | 1887-1887 | 1887-1887 | |
| Jack Hardy | 1877-06-23 | 1921-10-20 | 44.119 | C-OF | 6-0 | 185 | R | R | 1877-06-23 | Cleveland,OH | MLB | 1903-1910 | 1903-1910 | |
| Gil Hatfield | 1855-01-27 | 1921-05-26 | 66.119 | SS-3B | 5-9 | 168 | R | R | 1855-01-27 | Hoboken,NJ | MLB | 1885-1895 | 1885-1895 | |
| Arthur Irwin | 1858-02-14 | 1921-07-16 | 63.152 | SS | 5-8 | 158 | L | R | 1858-02-14 | Toronto,ON | MLB | 1880-1894 | 1880-1894 | |
| Bill Kuehne | 1858-10-24 | 1921-10-27 | 63.003 | 3B | 5-8 | 185 | R | R | 1858-10-24 | Leipzig,GE | MLB | 1883-1892 | 1883-1892 | |
| Hal Mauck | 1869-03-06 | 1921-04-27 | 52.052 | P | 5-11 | 185 | R | R | 1869-03-06 | Princeton,IN | MLB | 1893-1893 | 1893-1893 | |
| Barney McLaughlin | 0000-00-00 | 1921-02-13 | | P | 5-8 | 163 | R | R | | | MLB | 1884-1890 | 1884-1890 | |
| Tom McLaughlin | 1860-03-28 | 1921-07-21 | 61.115 | SS-2B | | 170 | R | R | 1860-03-28 | Louisville,KY | MLB | 1883-1891 | 1883-1891 | |
| Larry McLean | 1881-07-18 | 1921-03-24 | 39.249 | C | 6-5 | 228 | R | R | 1881-07-18 | Fredericton,NB | MLB | 1901-1915 | 1901-1915 | |
| Levi Meyerle | 0000-00-00 | 1921-11-04 | | P | 6-1 | 177 | R | R | | Philadelphia,PA | MLB | 1871-1884 | 1871-1884 | |
| Charlie Morton | 1854-10-12 | 1921-12-09 | 67.058 | OF | | 150 | R | R | 1854-10-12 | Kingsville,OH | MLB | 1882-1885 | 1882-1885 | |
| Alexander Nevin | 1850-10-03 | 1921-10-10 | 71.007 | 3B | | 0 | | | 1850-10-03 | Allegheny City,PA | MLB | 1873-1873 | 1873-1873 | |
| Hugh Nicol | 1858-01-01 | 1921-06-27 | 63.177 | OF | 5-4 | 145 | R | R | 1858-01-01 | Campsie,ST | MLB | 1881-1890 | 1881-1890 | |
| Tom O'Brien | 1860-06-22 | 1921-04-21 | 60.303 | 2B | 6-1 | 185 | R | R | 1860-06-22 | Salem,MA | MLB | 1882-1890 | 1882-1890 | |
| Henry Oberbeck | 1858-05-17 | 1921-08-26 | 63.101 | P | | 0 | | | 1858-05-17 | St. Louis,MO | MLB | 1883-1884 | 1883-1884 | |
| Laurie Reis | 1858-11-20 | 1921-01-24 | 62.065 | P | 5-9 | 160 | B | R | 1858-11-20 | Chicago,IL | MLB | 1877-1878 | 1877-1878 | |
| George Rettger | 1868-07-29 | 1921-06-05 | 52.311 | P | 5-11 | 175 | R | R | 1868-07-29 | Cleveland,OH | MLB | 1891-1892 | 1891-1892 | |
| Jack Robinson | 1880-07-15 | 1921-07-22 | 41.007 | C | | 0 | | R | 1880-07-15 | Portland,ME | MLB | 1902-1902 | 1902-1902 | |
| Socks Seybold | 1870-11-23 | 1921-12-22 | 51.029 | OF | 5-11 | 175 | R | R | 1870-11-23 | Washingtonville,OH | MLB | 1899-1908 | 1899-1908 | |
| Tom Vickery | 1867-05-05 | 1921-03-21 | 53.320 | P | 6-0 | 170 | | R | 1867-05-05 | Milford,NJ | MLB | 1890-1893 | 1890-1893 | |
| Joe Weber | 1862-02-15 | 1921-12-15 | 59.303 | OF | 5-9 | 167 | R | | 1862-02-15 | Hamilton,ON | MLB | 1884-1884 | 1884-1884 | |
| George Winkleman | 0000-00-00 | 1921-01-01 | | OF | | 0 | | | | | MLB | 1883-1883 | 1883-1883 | |
| 39 record(s) |