<p>Pursuing economic efficiency while curbing carbon emissions has become a core collective goal of the global community, and carbon emission efficiency provides a quantifiable analytical framework for the comprehensive evaluation of this dual objective. This study examines the spatiotemporal evolution of manufacturing agglomeration and carbon emission efficiency in China, employing the Spatial Durbin Model to analyze their spatial correlation and spillover effects. The results show an apparent rise in cities with medium-to-high carbon emission efficiency, mainly located in the Southeastern coastal area. The gap between carbon emission efficiency and manufacturing agglomeration levels across cities is gradually narrowing. Additionally, estimates from the Spatial Durbin Model indicate a significant spatial correlation, with manufacturing agglomeration having a negative local impact on carbon emission efficiency while causing positive spillover effects in neighboring cities. Essentially, regional economies form an interconnected organic system, which means a holistic perspective must be adopted in formulating regional policies. Cross-regional cooperation is therefore essential to foster coordinated development, advance industrial green transformation, and promote high-quality economic growth. This study clarifies the spatial interaction between manufacturing agglomeration and carbon emission efficiency in China, filling a gap in the existing knowledge that overlooks their spatial correlation. Policy implications emphasize agglomeration strategies, economic coordination, regional connectivity, and long-term support for sustainable manufacturing. The findings guide local governments on balancing manufacturing agglomeration with carbon efficiency, designing cross-regional environmental policies, and enhancing environmental performance. It also offers valuable insights for other emerging economies seeking to strike a balance between growth and carbon reduction.</p>