Flags that are red 148
Red is the most common colour on national flags: 148 of 191 use it. There is a banal reason - red dye was cheap and light-fast for centuries - and a symbolic one: on a great many flags red stands for blood shed.
All 148 countries
Afghanistan, Albania, Algeria, Andorra, Angola, Armenia, Australia, Austria, Azerbaijan, Bahrain, Bangladesh, Belarus, Belgium, Belize, Benin, Bolivia, Brunei, Bulgaria, Burkina Faso, Burundi, Cambodia, Cameroon, Canada, Cape Verde, Central African Republic, Chad, Chile, China, Colombia, Comoros, Costa Rica, Croatia, Cuba, Czech Republic, DR Congo, Denmark, Djibouti, Dominican Republic, Ecuador, Egypt, Equatorial Guinea, Eritrea, Eswatini, Ethiopia, Fiji, France, Gambia, Georgia, Germany, Ghana, Guinea, Guinea-Bissau, Guyana, Haiti, Hungary, Iceland, Indonesia, Iran, Iraq, Italy, Japan, Jordan, Kenya, Kiribati, Kuwait, Kyrgyzstan, Laos, Latvia, Lebanon, Liberia, Libya, Liechtenstein, Lithuania, Luxembourg, Madagascar, Malawi, Malaysia, Maldives, Mali, Malta, Mauritania, Mauritius, Mexico, Moldova, Monaco, Mongolia, Montenegro, Morocco, Mozambique, Myanmar, Namibia, Nepal, Netherlands, New Zealand, North Korea, North Macedonia, Norway, Oman, Palestine, Panama, Papua New Guinea, Paraguay, Peru, Philippines, Poland, Portugal, Qatar, Republic of the Congo, Romania, Russia, Samoa, Sao Tome and Principe, Senegal, Serbia, Seychelles, Singapore, Slovakia, Slovenia, South Africa, South Korea, South Sudan, Spain, Sri Lanka, Sudan, Suriname, Switzerland, Syria, Taiwan, Tajikistan, Thailand, Timor-Leste, Togo, Tonga, Trinidad and Tobago, Tunisia, Turkey, Turkmenistan, Uganda, United Arab Emirates, United Kingdom, United States, Uzbekistan, Vanuatu, Venezuela, Vietnam, Yemen, Zambia, Zimbabwe