Human natural killer (NK) cells develop in secondary lymphoid tissues (SLTs) through distinct stages. We identified two SLT lineage (Lin)⁻CD34⁻CD117^+/−CD94⁺CD16⁻ "stage 4" subsets according to expression of the C-type lectin-like surface-activating receptor, NKp80: NKp80⁻ (stage "4a") and NKp80⁺ (stage "4b"). Whereas stage 4b cells expressed more of the transcription factors T-BET and EOMES, produced interferon-gamma, and were cytotoxic, stage 4a cells expressed more of the transcription factors RORγt and AHR and produced interleukin-22, similar to SLT Lin⁻CD34⁻CD117⁺CD94⁻CD16⁻ "stage 3" cells, whose phenotype overlaps with that of group 3 innate lymphoid cells (ILC3s). Co-culture with dendritic cells or transplantation into immunodeficient mice produced mature NK cells from stage 3 and stage 4a populations. These data identify NKp80 as a marker of NK cell maturity in SLTs and support a model of human NK cell development through a stage 4a intermediate with ILC3-associated features.