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The epidemiology of Moraxella species bloodstream infection (BSI) is poorly defined due to their rarity. We sought to determine the incidence, risk factors, and outcomes of Moraxella species BSI in a large Australian population. All Moraxella species BSIs in patients admitted to Queensland (population estimate 5 million) public health facilities between 2000 and 2019 and submitted to Queensland pathology laboratory-based surveillance were included. Clinical and hospitalisation data were matched with laboratory-based surveillance data. Incidence rate ratios (IRR) with 95% confidence intervals (CI) were calculated. In total, 375 incident Moraxella species BSI occurred during 86 million person-years of surveillance, with an annualised age and sex standardised incidence of 4.3 per million residents. Isolates were most commonly identified as M. catarrhalis (n = 128; 34%) and community-associated (n = 225; 60%). Incidence was highest in infants, with increasing age associated with lower incidence rate. Males were at higher risk (incidence 2.9 vs. 2.0 per million, IRR1.4; 95% CI, 1.2-1.8), this was most pronounced at age extremes. Two-thirds of adults and 43% of children with Moraxella BSI had at least one comorbid illness. When compared to infections in adults, children were more likely to have community-associated disease, and a head and neck source focus of infection. The all-cause 30-day case-fatality rate was 4% (15/375) and this was significantly higher among adults (14/191; 7% vs 1/183; 1%; p < 0.001). Our findings demonstrate the low burden of Moraxella species BSI in a state-wide cohort, for which young children have the highest risk., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)