The purpose of this study is to analyze the hat fashion worn by the British royal family. The research range has been limited to hats which Elizabeth II, Camilla Parker Bowles, and Kate Middleton wore from April 29, 2011 to April 11, 2014 when Kate Middleton married Windsor Prince William and became part of the royal family. The methods of the research were: previous studies and literature about the royal family were referred to, the function and types of hats were considered, and then the plasticity of the designs seen in hat fashion of the royal family were analyzed. The results are as follows: first, the shape of the hats of the British royal family: Three-dimensional shapes(84.2%) were the most frequent, the detailed shape of the hat Canotier(33.5%), Boater(12.7%) and Bowler(10.3%) had greater frequency. Second, the color of the hats were W(13.7%), Bk(10.5%), Y(9.8%), B(9.6%), YR/PB(9.4%) and RP(9.2%) color. The Color Combination is the Monochrome Color(62.3%), Analogous Color(16.1%), Accent Color(13.2%) and Complementary Color(8.4%) were most frequent. Third, the material of the hats were Felt(44.5%) and Straw(40.3%) were used most frequently. Finally, the decoration of hats were: Flowers(25.7%), String(25.0%), Ribbon(18.4%) and Feathers(17.9%) were the most common. This study can be utilized as basic data for effective styling and design ideas in the field of total fashion.