This dataset contains responses to questions 4.1, 4.2, 4.3, 4.3a, and 4.4 on cities emissions inventories in the 2020 Cities Questionnaire, as disclosed by cities through the CDP-ICLEI Unified Reporting System. The dataset includes data reported by the following cities: Ayuntamiento de Madrid, Bangkok Metropolitan Administration, City of Anchorage, City of Athens, City of Berlin, City of Boston, City of Buenos Aires, City of Delhi, City of Helsinki, City of Las Vegas, City of Paris, City of Perth, City of San Francisco, City of Stockholm, City of Sydney, City of Vancouver, Göteborgs Stad, Greater London Authority, Kyoto, La Paz, Municipalidad de Santiago, New York City, Prefeitura do Rio de Janeiro, Singapore Government, Stadt Zürich, The Executive Council, Govt of Dubai, Ville de Nyon, Wellington City Council, and Wuhan Municipal People's Government.