A balanced diet informed by sound nutrition knowledge is key for operational readiness and the health of military personnel. Unfortunately, research suggests that military personnel have inadequate dietary intakes. This study assessed general nutrition knowledge, diet quality and their association in Australian military personnel. A convenience sample of male military personnel (n 211) including Army soldiers and officers completed a validated general nutrition knowledge questionnaire (GNKQ) and FFQ. The GNKQ assessed knowledge of dietary guidelines (Section A), sources of nutrients (Section B), choosing everyday foods (Section C) and diet–disease relationships (Section D). The Australian Recommended Food Score (ARFS) was used to assess diet quality from FFQ data. Statistical analyses included the χ
2 test, Spearman’s correlation test, t test, median test, ANCOVA and ordinal logistic regression. The mean total GNKQ score was 52·7 %. Participants performed best on Section A (58·5 %) followed by Sections B (57·3 %) and C (57·0 %) and worst on Section D (31·0 %). Overall, officers scored significantly higher than soldiers (58·7 v. 51·9 %, P=0·001). Age was weakly but positively correlated with GNKQ total scores (r 0·307; P<0·0005), with no significant effects seen for level of education (P=0·463) or living arrangement (P=0·167). Overall ARFS was 37·6 (sd 7·7) (50·8 %) with officers scoring significantly higher than soldiers (54·7 v. 50·3 %, P=0·040). No demographic variables influenced total ARFS. The total GNKQ score had a significant, positive but weak relationship with total ARFS (r 0·179; P=0·009). Given the importance of nutrition to personnel health and operational readiness, initiatives to improve nutrition knowledge and diet quality are recommended in this population, especially in soldiers.