This section provides a detailed anatomical and functional characterization of thalamic regions relevant for deep brain stimulation (DBS), with emphasis on intralaminar, midline, anterior, and lateral nuclei. The intralaminar formation, particularly the CM–PF complex and CeM, is highlighted for its central position, basal ganglia connectivity, and emerging role in epilepsy and movement disorder modulation. Midline nuclei are described as small but highly interconnected structures implicated in limbic, cognitive, and affective processes, with translational relevance from animal models requiring cautious interpretation in humans. The anterior nuclei are presented as key components of the extended hippocampal network and established DBS targets in drug-resistant epilepsy, with outcome-related “sweet spots” linked to mammillothalamic pathway engagement. The lateral thalamic region is analyzed in terms of motor and sensory subdivisions, afferent entry zones, and fiber architecture critical for DBS targeting in movement disorders. Across regions, close spatial proximity of DBS targets and shared fiber contingents underscore the necessity of precise electrode localization, MRI–histology correlation, and pathway activation profiling to interpret stimulation effects and optimize clinical outcomes.