This dataset includes data files and script files for analysing population genetic structure, gene flow, lake growth rates and putative reproductive migratory behaviour of brown trout between lake habitat and both inflowing and outflowing spawning streams. The lake in question is Bunaveela Lough in the North of the Burrishoole catchment. The inflowing stream is the Fiddaunveela and the outflowing stream is the Goulaun. Genetic data generally include 14 microsatellite loci. Temperature data are in C. Fish lengths are in mm and distances are in m. None Suggested Citation: Finlay, Ross; McGinnity, Philip; Coughlan, Jamie; Kaufmann, Joshka; de Eyto, Elvira; Dillane, Mary; Poole, Russell; Rogan, Ger. (2019) Biological, behavioural and genetic data of brown trout (Salmo trutta) in lacustrine, lake-inflow and lake-outflow habitats. Marine Institute, Ireland. doi:10/df6b.