The Feni Island group is located at the southeastern end of the NW trending Ta-bar-Lihir-Tanga-Feni (TLTF) island chain, northeastern Papua New Guinea. This island chain is renowned for hosting alkaline magmas, geothermal activity, copper-gold mineralization and mining. The purpose of this paper is to present the geological observations of Feni Island within the context of the regional tectonic setting and evolution of the TLTF. The TLTF arc is a younger arc situated within the Greater Melanesian Arc, specifically within the New Ireland Basin bounded by New Ireland to the west and the extinct Kilinailau Trench in the east. The formation of the TLTF is attributed to post-subduction extensional tectonics relating to the opening of the Manus Basin and the magma is sourced from subduction-modified upper mantle. Normal, ex-tensional faulting is observed throughout the TLTF.