["Population, Space and Place, Volume 32, Issue 5, July 2026. ", "\nABSTRACT\nThe rapid growth of metropolitan regions is reshaping residents' mobility and attachment to places across scales. However, research on regional‐scale place attachment remains limited, particularly regarding how residents with different identities develop such attachment. Drawing on survey data from nine mainland cities in the Guangdong‐Hong Kong‐Macao Greater Bay Area (N = 1526), this study examines differences in regional attachment between locals and migrants, along with key influencing factors. A mobility–psychology pathway model is constructed to explain the formation of regional attachment. Findings reveal that work‐related and intra‐regional mobility enhance attachment, while city attachment and satisfaction with work and leisure contribute psychologically. Mechanisms vary between locals and migrants, offering new insights into place attachment and informing inclusive regional and urban policy.\n"]