An estimated 150 million people worldwide are homeless, and approximately 1.8 billion lack adequate housing. Housing is a key determinant of health and mitigates health disparities among homeless populations. However, how housing impacts the physical and mental health of homeless individuals remains unclear. This study investigated how housing status, type, and duration affect the physical health, anxiety, and depression of previously homeless individuals (PHI) in regional NSW, Australia. Using a mixed-methods, retrospective pre-post-test design, 48 participants (42 females, 6 males) from Homes North community housing in Armidale (n = 6), Gunnedah (n = 5), Inverell (n = 3), Moree (n = 2), and Tamworth (n = 32) completed the SF-36, GAD-7, and PHQ-9 health surveys and in-depth interviews. The interviews explored factors contributing to homelessness, the barriers faced during homelessness and the transition to stable housing, perceptions of health and its management, and the support available during these times. Results from repeated measures MANOVA revealed statistically significant improvements in physical and mental health after transitioning to stable housing. Participants reported reduced role limitations due to physical health, decreased bodily pain, improved general health, and significant reductions in anxiety and depression. Notably, participants in the Start Safely program, who experienced housing instability due to domestic and family violence (DFV), showed significant reductions in bodily pain, anxiety, and depression. The duration of stable housing did not significantly impact health outcomes. Thematic analyses identified DFV, intimate partner violence (IPV), family conflict, and lack of affordable housing as major contributors to homelessness. Couch-surfing and rough sleeping were the most frequently reported types of homelessness. High costs of transitional accommodations and bureaucratic complexities were key barriers to achieving stable housing. The absence of family support exacerbated the challenges of homelessness, while friends and organisational support provided essential temporary accommodation and emotional support. Stable housing was consistently linked to improvements in physical and mental health, as well as an increased sense of safety, security, and social inclusion. These findings underscore the importance of stable housing as a key determinant of health. Addressing the long-term effects of homelessness, implementing diverse housing programs, and providing comprehensive supportive services during and after the transition to stable housing is essential for optimising health outcomes for the homeless and vulnerable populations, especially in regional and remote areas. Future research should investigate how individual characteristics impact the changes in physical and mental health across different housing programs to improve these outcomes.