This paper examines financial interconnectedness in ASEAN+3 using BIS Locational Banking Statistics to map the cross-border claims and liabilities of ASEAN+3 banks and analyzes contagion risks via daily market and financial asset prices, based on the Diebold and Yilmaz (2012, 2014) methodology. The findings indicate that even as intraregional interconnectedness is rising, the region remains vulnerable to shocks from major advanced economies. ASEAN+3 economies also generate outward spillovers both within and beyond the region. This interconnectedness highlights the need for stronger regional surveillance, enhanced cross-border data sharing, regional stress testing, improved supervision, and robust liquidity support.