<jats:title>Abstract</jats:title><jats:p>Four new indolo‐sesquiterpenes – dixiamycins A (<jats:bold>1</jats:bold>) and B (<jats:bold>2</jats:bold>), oxiamycin (<jats:bold>3</jats:bold>), and chloroxiamycin (<jats:bold>4</jats:bold>) – were isolated from a marine‐derived Actinomycete and characterized, together with the known compound xiamycin A (<jats:bold>5</jats:bold>). Dixiamycins A (<jats:bold>1</jats:bold>) and B (<jats:bold>2</jats:bold>) are the first examples of atropisomerism of naturally occurring N‐N‐coupled atropo‐diastereomers, with a dimeric indolo‐sesquiterpene skeleton and a stereogenic N‐N axis between sp<jats:sup>3</jats:sup>‐hybridized nitrogen atoms. Solution TDDFT ECD calculations were utilized to ascertain the axial chirality of <jats:bold>1</jats:bold> and <jats:bold>2</jats:bold>, and rotational barriers and transitions states of the inversion were calculated. Oxiamycin (<jats:bold>3</jats:bold>) contains a seven‐membered 2,3,4,5‐tetrahydrooxepine ring. The two dimeric compounds <jats:bold>1</jats:bold> and <jats:bold>2</jats:bold> showed better antibacterial activities than the monomers <jats:bold>3</jats:bold>–<jats:bold>5</jats:bold>.