Interest in triads and triadic research settings for the study of inter-organizational issues is growing. A literature review of inter-organizational studies, claiming a use of triadic research design, shows that the terms “triad” and “triadic” have been used to describe many different types of inter-organizational phenomena. However, not all studies involving a context of three actors are actually examining triads. This paper offers a robust definition of three-actor constellations qualifying as triads. Moreover, it elaborates on different types of inter-organizational triads, based on two aspects of collectivity; cohesion and the ability to act as a single entity. The definition of inter-organizational triads and the categorization of different types of triads will hopefully encourage further studies of triads; the smallest and simplest network which offers insights, which cannot be achieved in the study of single actors or dyads.