Magnetoencephalography (MEG) has a unique combination of attributes allowing the probing of brain function, with resolution of space, time, and spectral content. These attributes lend themselves to the study of disorders characterized by no conspicuous structural brain anomalies, but rather anomalies of neural signals and communication. This chapter reviews the use of diverse MEG techniques and paradigms to study one such disorder, autism spectrum disorder (ASD). The authors focus on MEG as a probe of auditory and face processing anomalies in ASD. Impairments in auditory processing in ASD have been identified as objective markers of language and communication ability, general cognitive ability, and abnormal sensory sensitivity. Most MEG studies have observed that atypical auditory responses such as components of the early auditory evoked field (i.e., M50, M100), mismatch fields, or gamma-band oscillatory activity occur in individuals with ASD compared with typically developing children. Maturational trajectories of such measures also deviate from neurotypical patterns. Similarly, impairments in face perception are characteristic of ASD and have been a large focus of MEG studies, as a model probe for the social impairment phenotype. MEG research has demonstrated atypical source localization of activity during face processing in children through adults as well as in executive functions, including working memory and inhibition. Interregional differences in synchrony of neural oscillations have been elaborated by MEG in emotional face processing tasks, with visual perceptual processing underscoring gamma-band atypicalities in ASD. We highlight MEG as a promising approach for establishing clinical biomarkers of ASD and informing mechanistic neuroscience.