Greenhills School is a member of the
Michigan High School Athletic Association (MHSAA) and offers the following sports: • Boys:
tennis,
baseball,
basketball,
cross country,
golf,
lacrosse,
soccer,
track and field, and
swimming & diving • Girls:
tennis,
basketball,
cross country,
field hockey,
golf,
soccer,
softball,
track and field,
swimming & diving and
volleyball •
Coed:
equestrian. However, both the track and cross country teams have co-ed practices. The boys tennis team won the Division 4 Lower Peninsula state championship in 2003–4, 2006-7 and 2008-9 through 2015–16. They also won again in 2018. In 2019 the team moved up to division three and won their first state championship there. The team went undefeated that season and ended up as the top ranked team across all divisions - #1 in the power rankings. Their coach, Eric Gajar, was named coach of the year for the state of Michigan. Since 2001,
MHSAA has not crowned a true state champion in tennis, opting instead for separate tournaments for the Upper and Lower peninsulas. In 2017, the men's soccer team won the Division 4 state championship. Jerry Tucker, a senior, scored the lone goal of the match to send the Gryphons to a 1–0 victory. In January 2023, Gajar was inducted into the Michigan High School Tennis Coach Association (MHSTeCA) Hall of Fame after being a 10-time MHSTeCA Coach of the Year and named the National Federation of High School Coaches Association Coach of the Year in 2016. ==Renovation==