Last name ซิดนีย์ (Sydney 
, Sitni 
, ซิดนีย์ ) , globally, is a common family name. The cognomen ซิดนีย์ is habitual in Saint Lucia, where it is quite a common surname, Trinidad and Tobago, and Mauritius, where it is quite a rare surname. In absolute terms, it most frequently occurs in Nigeria, Australia, and the United States. More prevalently, ซิดนีย์ is the forename as well as the last name.