Electroencephalography (EEG) is a widely used and cost-effective neuroimaging technique, though it has limited spatial resolution. Combining EEG with other neuroimaging modalities significantly enhances its diagnostic utility. Recent technological advancements have paved the way for multimodal neuroimaging, integrating various techniques to deepen our understanding of brain function through data fusion. This chapter will examine the integration of EEG (and magnetoencephalography-MEG) with magnetic resonance imaging (MRI) for source localization, functional magnetic resonance imaging (fMRI), positron emission tomography (PET), and neuromodulation/neurostimulation methods. Such integration not only improves source localization but also opens new therapeutic avenues for brain disorders. Special attention will be given to the critical role these combined techniques play in epilepsy research and treatment, alongside their broader clinical applications, highlighting their significance in both research and clinical settings.