IntroductionThe aim of this integrative review is to understand (1) how parents in specific populations engage with online breastfeeding, chestfeeding, or lactation support groups, (2) how these support groups influence extended breastfeeding duration and other outcomes, and (3) whether the use of support groups by these specific populations has changed since the start of the COVID‐19 pandemic.MethodsOf the articles identified across 4 electronic databases, 10 studies met the inclusion criteria; they were published between 2013 and 2023, written in English, and focused on the use of online peer support groups for breastfeeding, chestfeeding, and lactation support in specific populations. Eight of these studies are qualitative, 1 is a randomized controlled trial, and 1 is mixed methods.ResultsEight themes were identified: (1) overcoming lack of real world support, (2) normalization, (3) practical support, (4) emotional support and shared experiences, (5) building a bridge to in‐person relationships, (6) reciprocity and activism, (7) self‐efficacy and outcomes, and (8) issues with online support groups.DiscussionSpecific subpopulations of breastfeeding, chestfeeding, and lactating parents and their partners found comfort in online support groups because they normalized more unique feeding practices and offered a space to provide and receive encouragement. Additionally, this review includes fathers/partners as a previously ignored subpopulation who benefit from education and support with breastfeeding, chestfeeding, and lactation. This subpopulation is also an area for expanded research on the use of online support groups by partners of lactating parents.