The Royal Flags of Thailand (Thai: ธงประจำพระองค์) are flags that are usually flown in Thailand along with the National flag to honor the King as well as the Royal Family of Thailand. Unlike the Royal Standards that are only displayed in special ceremonies and in particular locations, the royal flags are a ubiquitous sight all over Thailand. They are not commonly seen, however, outside of the country.
The main royal flag is that of the King of Thailand, Maha Vajiralongkorn, known as the "Tenth king" (Rama X). The flag of the previous monarch King Bhumibol Adulyadej and the flag for Queen Dowager Sirikit is still widely used. These flags are in plain colors with their respective royal cyphers. Other members of the royal family, like Princess Maha Chakri Sirindhorn and Princess Chulabhorn Walailak also have their own plain-color flags, but these are not seen very often, except at ceremonies personally led by them.
The royal flags are not only used officially, but also unofficially. They are displayed by Thai citizens of any social class or background at any location, usually beside the Thai flag, as a homage to their King. Honoring the royal family is a characteristic feature of Thai culture.
These flags are sold at most small stores and grocery stores in every town and village of Thailand. They come in many different sizes. Usually the symbol is printed only on one side of the flag.
The King's flag is in yellow, the color of Monday, the day of his birth. It always has a symbol in the middle. There are a variety of symbols, but recently most king's flags have different symbols, such as the symbol marking King Bhumibol's 80th birthday or the one commemorating the 60th anniversary of King Bhumibol's accession to the throne.