Kinship in natural marine fish systems has been little explored in part due to limitations of available genomic approaches. This is especially true for very abundant and commercially exploited marine pelagic fish with broadcast spawning. Recent advances in genomics have however, facilitated an improved understanding of population structure in marine systems at fine geographic scales. Here, we identify kinship structure in an aggregation of Atlantic herring (Clupea harengus) juveniles. We identified 11 half-sib pairs using a suite of 92 sequenced microsatellite DNA markers in a sample of N=1391 herring individuals comprising two cohorts (ages 0+ and 1+) collected from the 2018 Fall research survey of the Southern Gulf of St. Lawrence. In addition, we were also able to detect a full-sib pair using the combination of half-sib pairs and whole mitochondrial DNA (mtDNA) analysis. This study suggests the presence of kinship structure in a juvenile herring aggregation three months or more post hatching with implication for our understanding of herring early life history.