Charge transport is a key bulk property of organic semiconductors applied in electronic and optoelectronic devices, such as organic field-effect transistors (OFTEs), solar cells, light-emitting diodes (LEDs), and photodiodes. Over the last few decades, much attention has been focused on electron-rich p-type charge transport materials, which form the majority of π-conjugated organic semiconductors. More recently, molecular design strategies have been developed that incorporate electron deficient units in conjugated structures, leading to new materials with excellent electron transport properties. This thematic issue features reviews and original papers covering the latest research in the design and application of n-type organic semiconductors for a range of different types of devices, and aims to showcase the state-of-the-art in organic electron transport materials.