Language is a uniquely human cognitive function which plays a defining role in our psychological and social traits. Despite the obvious importance of language and speech, they remain one of the least understood human cognitive functions with the cortical underpinnings of these crucial skills still obscure. In recent decades, a large amount of data that account for the neural bases of language processes in both children and adults have been acquired through the use of many advanced neurophysiology techniques. These include high-density electroencephalography, magnetoencephalography, functional magnetic-resonance tomography, transcranial magnetic stimulation, transcranial direct current stimulation, and eye-tracking. The combined use of these approaches continues to shed light on brain mechanisms of language acquisition, comprehension and processing, on speech disorders and their treatment, and on interactions between language and other neurocognitive systems and functions. The aim of this Research Topic in Frontiers in Human Neuroscience is to provide a state-of-the-art overview of this diverse and multidisciplinary area of research, with special emphasis on bridging the gap between different methodologies.