Potassium (K+) homeostasis is crucial for neural function, as it directly influences membrane polarization. Under physiological conditions, extracellular K+ concentration ([K+]o) fluctuates between 2 and 5 mM, while pathological increase above 10 mM is associated with disorders such as epilepsy. Astrocytes, the most abundant glial cells, regulate [K+]o through two primary mechanisms: K+ uptake via Na+/K+ ATPases and spatial buffering, mediated by Kir4.1 channels and a gap–junction coupled network. Despite significant progress in our understanding of astrocyte physiology, a comprehensive picture of the astrocytic mechanisms governing ion homeostasis remains elusive, largely due to the limited availability of research tools specifically targeting astrocytes. This chapter explores the sources and sinks of K+ in the central nervous system and the mechanisms by which astrocytes regulate [K+]o. We also review existing research tools and highlight key knowledge gaps that need to be addressed to further elucidate the astrocytic functions involved in K+ homeostasis regulation.