A capacitor for an implantable medical device has a housing. The housing has a first outer side and a second outer side facing away from the first outer side. The two outer sides are connected to one another via a lateral outer side of the housing running in a circumferential direction of the housing. The lateral outer side has a straight first portion and an arcuate second portion. The first portion has two end regions, which are connected to one another via a middle region of the first portion. The end regions are each connected to the second portion. The capacitor has an electrical terminal arranged on the middle region of the first portion of the lateral outer side, which electrical terminal has two contact surfaces for electrically contacting the capacitor. A capacitor assembly and an implantable medical device are formed with the above describe capacitor.
