| Player | Pos | Seasons | Born | Birthplace | |
| Eddie Kasko | SS | 1964-65 | Jun 27, 1931 | Elizabeth | NJ |
| Matt Kata | 2B | 2009 | Mar 14, 1978 | Avon Lake | OH |
| Scott Kazmir | P | 2015 | Jan 24, 1984 | Houston | TX |
| Mick Kelleher | SS | 1974 | Jul 25, 1947 | Seattle | WA |
| Russ Kemmerer | P | 1962-63 | Nov 1, 1930 | Pittsburgh | PA |
| Tony Kemp | OF/2B/DH | 2016-19 | Oct 31, 1991 | Franklin | TN |
| Jeff Kent | 2B | 2003-04 | Mar 7, 1968 | Bellflower | CA |
| Matt Keough | P | 1986 | Jul 3, 1955 | Pomona | CA |
| Jeff Keppinger | 2B/3B | 2009-11 | Apr 21, 1980 | Miami | FL |
| Charlie Kerfeld | P | 1985-87, 1990 | Sep 28, 1963 | Knob Noster | MO |
| Dallas Keuchel | P | 2012-18 | Jan 1, 1988 | Tulsa | OK |
| Darryl Kile | P | 1991-97 | Dec 2, 1968 | Garden Grove | CA |
| Hal King | C | 1967-68 | Feb 1, 1944 | Oviedo | FL |
| Bob Knepper | P | 1981-89 | May 25, 1954 | Akron | OH |
| Alan Knicely | C/OF | 1979-82 | May 19, 1955 | Harrisonburg | VA |
| Ray Knight | 1B/3B | 1982-84 | Dec 28, 1952 | Albany | GA |
| Randy Knorr | C | 1996-97, 1999 | Nov 12, 1968 | San Gabriel | CA |
| Mark Knudson | P | 1985-86 | Oct 28, 1960 | Denver | CO |
| Doug Konieczny | P | 1973-75, 1977 | Sep 27, 1951 | Detroit | MI |
| Erik Kratz | C | 2016 | Jun 15, 1980 | Telford | PA |
| Marc Krauss | OF/1B/DH | 2013-14 | Oct 5, 1987 | Deshler | OH |
| Gary Kroll | P | 1966 | Jul 8, 1941 | Culver City | CA |