Jefferson High School has a baseball team at the freshman, sophomore, and varsity levels.
- Varsity head coach: Mike Chrismar
- Varsity assistant coach: Adam Thompson
- Varsity assistant coach: Alex Bendlage
- Sophomore head coach: Gordy Nordgren
- Sophomore assistant coach: Jon Cross
- Sophomore assistant coach: Roger Gruwell
- Freshman coach: Michael Boddicker
- Freshman coach: Matt Hilby
J-Hawk baseball records
| Season | Career | |||||
|---|---|---|---|---|---|---|
| Plate appearances | Chad De Maria | 170 | 1995 | Spencer Van Scoyoc | 477 | 2016 |
| Nick Nordgren | 477 | 2005 | ||||
| Batting average | Ian Mattiace | .556 | 1998 | Kellen Sweeney | .456 | 2010 |
| Hits | Travis Bennett | 73 | 2006 | Spencer Van Scoyoc | 181 | 2016 |
| Runs | Jeremy Schlotterbeck | 70 | 1998 | Dave Konigsmark | 146 | 1991 |
| Runs batted in | Jeremy Lewis | 72 | 1991 | Jeremy Lewis | 150 | 1991 |
| Home runs | Ian Mattiace | 23 | 1998 | Ian Mattiace | 37 | 1998 |
| Triples | Mike Curran | 6 | 1971 | Mike Bruner | 10 | 1999 |
| Randy Schneekloth | 10 | 1988 | ||||
| Travis Bennett | 10 | 2005 | ||||
| Nick Nordgren | 10 | 2005 | ||||
| Doubles | Brayden Frazier | 24 | 2017 | Brayden Frazier | 51 | 2018 |
| Walks | Rick Brown | 30 | 1982 | Jim Ferguson | 82 | 1971 |
| Stolen bases | Harrison Gerber | 33 | 2008 | Mike Mims | 50 | 1987 |
| Harrison Gerber | 50 | 2008 | ||||
| Put outs | Blake De Maria | 382 | 1971 | Steve Schamberger | 651 | 1973 |
| Assists | Kellen Sweeney | 116 | 2008 | Brayden Frazier | 260 | 2018 |
| Wins | Kent Clark | 18-3 | 1994 | Colin Mattiace | 28-3 | 1992 |
| Earned run average | Doug Winders | 0.39 | 1961 | Dan Dalziel | 0.52 | 1971 |
| Strike outs | Bruce Barber | 195 | 1974 | Steve Rooks | 294 | 1976 |
| Innings pitched | Bruce Barber | 139 | 1974 | Mark Tschopp | 237 | 1968 |
| Team wins | Gordy Nordgren/Mike Kuba | 38-5 | 2005 |
Team honors
| State champion | 1961 |
| State runner-up | 1970 |
| State qualifier | 1961, 1964, 1970, 1978, 1989, 1991, 1995, 1996, 1998, 2018 |
| MVC champions | 1972, 1973, 1987, 1988, 1989, 1991, 1998, 2004, 2005, 2015 |
| Metro champions | 1970, 1972, 1973, 1974, 1975, 1976, 1977, 1977, 1982, 1983, 1987, 1991, 1998, 2009, 2018 |