[3][4] After graduating with a bachelor's degree in business administration and economics in 1979, Fennelly became a full-time assistant coach with William Penn.

[4] At the University of Toledo, Fennelly was head coach from 1988 to 1995 and had a cumulative record of 166–53, with a .758 winning percentage that remains the best in the Mid-American Conference.

[4] As of the 2016–17 season, Fennelly has led Iowa State to 17 appearances in the NCAA Tournament, including Elite Eight qualifications in 1999 and 2009 and the Sweet Sixteen in 2000, 2001, and 2010.

[5] Iowa State has spent considerable time in the Associated Press national poll, including 34 weeks in the Top 10.

In 1998, Fennelly finished as the 1998 runner-up behind Pat Summitt of Tennessee for the Associated Press Women's Coach of the Year award.

[5] Fennelly served as an assistant coach of the U18 team representing the US at the 2008 FIBA Americas U18 Championship for Women in Buenos Aires, Argentina.

[3] He and his wife, Deb, have two sons, Billy and Steven, both of whom also worked for their father's coaching staff at Iowa State.