Siderophores are low molecular weight iron-chelating molecules that many organisms secrete to scavenge ferric iron from the environment. While cyanobacteria inhabit a wide range of environments with poor iron availability, only two siderophore families have been characterized from this phylum. We sought to investigate siderophore production in the marine genus, Leptolyngbya. A 12 open reading frame (14.5 kb) putative nonribosomal peptide synthetase-independent siderophore biosynthesis gene cluster, identified in the genome of Leptolyngbya sp. PCC 7376, was cloned and heterologously expressed in Escherichia coli. Under iron-limiting conditions, expression strains harbouring the first seven genes (lidA to lidF), produced a potent siderophore, which was subsequently identified via UPLC-MS/MS and NMR as schizokinen. The enzymes encoded by the remaining genes (lidG1 to lidG5) did not appear to be active in E. coli, therefore their function could not be determined. Bioinformatic analysis revealed gene clusters with high homology to lidA to lidF in phylogenetically and biogeographically diverse cyanobacteria, suggesting that schizokinen-based siderophore production is widespread in this phylum. Siderophore yields in E. coli expression strains were significantly higher than those achieved by Leptolyngbya, highlighting the potential of this platform for producing siderophores of ecological and industrial value.