While sibling relationships are known to be important for children's social and emotional well-being, little is known about sibling relationships when both siblings are deaf or hard-of-hearing (DHH). In-depth interviews were conducted with 10 young DHH adults (20-30 years old) who had studied in mainstream schools to explore their retrospective experiences of growing up with a DHH sibling. Interviews were analyzed using interpretive phenomenological analysis. Findings revealed two superordinate themes: (1) sibling relationship and sense of self and (2) family coping and relationships, with each superordinate theme containing several subthemes. Findings highlighted the various ways sibling relationships contribute to siblings' psychological development, identity formation, and coping with deafness. Potential challenges were identified, as well as the role of parents' attitudes and coping with hearing loss in promoting supportive sibling relationships. Parents and professionals should be aware of the valuable and unique aspects of DHH siblingship and attend to important relationship aspects such as sibling communication, sibling comparisons, and parental differential treatment.