Known as one of the most energetic and charismatic coaches in Ohio who made a reputation on rebuilding programs, Jack led his teams to 333 victories as a head coach in Ohio and West Virginia. The last 15 years at Lancaster High School where he is the schools all time winningest  basketball coach. Jack started his coaching career as an assistant coach at Marshall University in the 1979-80 season for the Thundering Herd. He, at 22 years of age, then took over the head coaching position at Spencer High School. While at Spencer, West Virginia, Greathouse led the Yellow Jackets to three sectional championships, two conference championships and three regional appearances, twice in the regional finals.

In the 1987-88 season, Jack took over the Marietta High School Tigers. After a 0-5 start, he led the Tigers to 13 wins in the next 18 games in route to a sectional championship and a district final.

After only a season at Marietta, Jack took the basketball position at Lancaster High School in 1988, where he served as head coach until 2003. Geathouse helped build them into one of the states premier programs averaging 15 wins per season. They were frequently in area and state rankings and won multiple sectional championships. Jack led the Gales to the state tournament in 1991 losing in overtime to West Chester Lakota. He coached many all conference, district and Ohio players including his son, Kyle, who was the OHSBCA Division I Player of the Year in 2003.

In Jack’s career he has won many Coach of the Year Awards. Among them OHSBCA, AP Southeastern and Central District (five times). He was chosen for the District 11 Hall of Fame in 2009.

Through all his successes, Greathouse has always given credit to all his players, coaches, staff, administration, parents and fans. Jack’s number one team has been his family, wife Sandy, children Jodi and Kyle as well as son-in-law Derek, grandson Mason and his parents, Jack  and Shirley (deceased) Greathouse, Sr.

Jack’s dedication and commitment for education continues as he is the current principal at Lancaster High School.