The global burden of sepsis is concentrated in sub-Saharan Africa, where extensive pathogen diversity and limited laboratory capacity challenge targeted antimicrobial management of life-threatening infections. In this context, established and emerging rapid pathogen diagnostics may stratify sepsis patients into subgroups with prognostic and therapeutic relevance. In a prospective cohort of adults (age $18 years) hospitalized with suspected sepsis in Uganda, we stratified patients using rapid diagnostics for HIV, tuberculosis (TB), malaria, and influenza, and compared clinical characteristics and 30-day outcomes across these pathogen-driven subgroups. From April 2017 to August 2019, 301 adults were enrolled (median age, 32 years [interquartile range, 26–42 years]; female, n 5 178 [59%]). A total of 157 patients (53%) were HIV infected. Sixty-one patients (20%) tested positive for malaria, 52 (17%), for TB (including 49 of 157 [31%] HIV-infected patients), and 17 (6%), for influenza. Co-infection was identified in 33 (11%) patients. The frequency of multi-organ failure, including shock and acute respiratory failure, was greatest among patients with HIV-associated TB. Mortality at 30 days was 19% among patients with malaria, 40% among patients with HIV-associated TB, 32% among HIV-infected patients without microbiological evidence of TB, 6% among patients with influenza, and 11% among patients without a pathogen identified. Despite improvements in anti-retroviral delivery, the burden of sepsis in Uganda remains concentrated among young, HIV-infected adults, with a high incidence of severe HIV-associated TB. In parallel with improvements in acute-care capacity, use of rapid pathogen diagnostics may enhance triage and antimicrobial management during emergency care for sepsis in sub-Saharan Africa, and could be used to enrich study populations when trialing pathogen-specific treatment strategies in the region.