Many microorganisms obtain iron through siderophore ligands that contain catecholate, hydroxamate, α-hydroxycarboxylate, or diazeniumdiolate coordinating groups. By combining genome mining tools such as antiSMASH with targeted searches for genes that encode particular biosynthetic features on specific functional groups, we have uncovered the widespread presence of novel peptidic siderophores. Among the diverse class of peptidic siderophores, β-hydroxyaspartate frequently serves as an Fe(III)-binding ligand. The biosynthesis of β-hydroxyaspartate is intriguing due to the stereoselective control of hydroxylation, which is catalyzed by non-heme iron enzymes. A newly identified class of tris-catechol siderophores in marine and pathogenic microbes represents a variation of enterobactin, incorporating a combinatorial mix of D- and L- cationic amino acids. The chirality of these amino acids influences the stereochemistry at the Fe(III) binding site, which significantly affects microbial growth. More recently, a new class of siderophores, featuring a Fe(III)-binding diazeniumdiolate ligand, has been discovered. The biosynthesis of graminine, the amino acid containing the diazeniumdiolate group, is catalyzed by other iron enzymes. New developments in the bioinorganic chemistry of these siderophores will be presented.