Fathers are underrepresented in interventions focussing on child well-being, yet research suggests their involvement may be critical to enhancing intervention effectiveness. This study aimed to provide the first Australian benchmark of rates of father attendance across several child mental health services. Retrospective casefile reviews were conducted to obtain data on father and mother attendance at 10 Australian child mental health services. A total of 2128 casefile records were retrospectively examined to extract family-level data. The main outcome measures were rates of father and mother attendance at sessions involving parents, and rates of father- and mother-instigated referral to services. Across services, fathers attended on average 48.2% (range 39.7% to 72.0%) of total parent sessions, with an average of 68.4% (range 53.1% to 88.1%) of fathers attending at least one session. Mothers attended sessions at significantly higher rates; an average of 92.8% of total parent sessions and 96.9% attendance for at least one session. For self-referred families, on average 12.6% of referrals were from fathers, and 87.4% were from mothers. These results indicate that rates of father attendance at Australian child mental health services vary, but are significantly lower than attendance rates for mothers. This may compromise the quality and outcomes of child mental health services in Australia. Routine monitoring of rates of father attendance is needed, as are strategies to enhance father engagement.