Self-compassion, defined as a mindful way of coping with pain and suffering by showing kindness, care, and concern towards the self, may improve psychological adjustment in people living with a chronic physical health condition (CPHC). Various studies illustrate that self-compassion is associated with positive outcomes in general. The aim of this systematic review is to establish the effect of compassion-related therapies on self-compassion specifically in people with CPHCs. Secondary aims are to (a) establish the effect on other psychological and physiological outcomes and (b) explore the relative effectiveness of different therapy types among those identified. Cochrane, Embase, Medline, PsycINFO, and CINAHL databases were searched using "compassion" AND "chronic disease" AND "psychological outcomes" and their synonyms, from 2004 to March 2019. Eligible studies had an experimental design using a self-compassion scale with an adult population. Risk of bias (RoB) was assessed using the Cochrane RoB tool. Effect sizes were calculated for study outcomes. Fifteen studies, including a total of 1,190 participants, 7 different CPHCs, and 11 types of therapies, were included in the review. Nearly all included therapies significantly increased self-compassion with medium to large effect sizes, and reported positive outcomes, such as decreased depression. None of the therapy types appeared clearly superior to the others. Findings from this review show that included therapies increased self-compassion and improved various outcomes, which may represent clinically significant benefits for patients. However, there is a need to further understand how self-compassion exerts its benefits and determine the best methods to increase self-compassion.