Galicia is an Autonomous Community located in the north-west of Spain. As a starting point to implement mitigation and adaptation measures to climate change, a regional greenhouse gas (GHG) inventory is needed. So far, the only regional GHG inventories available are limited to the territorial emissions of those production activities which are expected to cause major environmental degradation. An alternative approach has been followed here to quantify all the on-site (direct) and embodied (indirect) GHG emissions related to all Galician production and consumption activities. The carbon footprint (CF) was calculated following the territorial life cycle assessment (LCA) methodology for data collection, that combines bottom-up and top-down approaches. The most up-to-date statistical data and life cycle inventories available were used to compute all GHG emissions. This case study represents a leap of scale when compared to existing studies, thus addressing the issue of double counting, which arises when considering all the production activities of a large region. The CF of the consumption activities in Galicia is 17.8 ktCO2e/year, with 88% allocated to Galician inhabitants and 12% to tourist consumption. The proposed methodology also identifies the main important contributors to GHG emissions and shows where regional reduction efforts should be made. The major contributor to the CF of inhabitants is housing (32%), followed by food consumption (29%). Within the CF of tourist consumption, the share of transport is highest (59%), followed by housing (26%). The CF of Galician production reaches 34.9 MtCO2e/y, and its major contributor is electricity production (21%), followed by food manufacturing (19%). Our results have been compared to those reported for other regions, actions aimed at reducing GHG emissions have been proposed, and data gaps and limitations identified.