Voltage-gated potassium channels (VGKCs) are transmembrane channels specific for potassium and sensitive to voltage changes in the cell's membrane potential. During action potentials, they play a crucial role in returning the depolarized cell to a resting state.

Alpha subunits form the actual conductance pore. Based on sequence homology of the hydrophobic transmembrane cores, the alpha subunits of voltage-gated potassium channels are grouped into 12 classes. These are labeled K_vα1-12. The following is a list of the 40 known human voltage-gated potassium channel alpha subunits grouped first according to function and then subgrouped according to the K_v sequence homology classification scheme:

slowly inactivating or non-inactivating

rapidly inactivating

Passes current more easily in the inward direction (into the cell, from outside).

Unable to form functional channels as homotetramers but instead heterotetramerize with K_vα2 family members to form conductive channels.

Beta subunits are auxiliary proteins that associate with alpha subunits, sometimes in a α₄β₄ stoichiometry. These subunits do not conduct current on their own but rather modulate the activity of K_v channels.

Proteins minK and MiRP1 are putative hERG beta subunits.