高电荷态离子（Highly Charged Ion，简称HCI），是指处在高度带电状态的离子。高能的相撞（如太阳风）或是吸收了高能量的光子让这些离子损失了许多的电子。例如在日冕里发现的正13价铁（Fe，又称Fe XIII），及需要极高能量产生的「裸铀」（铀核，U）。HCI在自然界中存在于日冕、活动星系核、超新星残骸以及恒星吸积盘。大部分的可见物质也都由HCI构成。为了引发核融合反应而使用的电浆也会经由「电浆障壁反应」（plasma-wall interaction）产生HCI。在实验室中能经由重离子加速器及电子束离子阱（Electron-beam ion trap）来产生及研究。

Highly charged ions (HCI) are ions in very high charge states due to the loss of many or most of their bound electrons by energetic collisions or high-energy photon absorption. Examples are 13-fold ionized iron, Fe or Fe (XIV) in spectroscopic notation, found in the Sun's corona, or naked uranium, U, bare all bound electrons, which requires very high energy for its production. HCI are found in stellar coronae, in active galactic nuclei, in supernova remnants, and in accretion disks. Most of the visible matter found in the universe consists of highly charged ions. High temperature plasmas used for nuclear fusion energy research also contain HCI generated by the plasma-wall interaction (see Tokamak). In the laboratory, HCI are investigated by means of heavy ion particle accelerators and electron beam ion traps.