Surname Сидги (Ruhulla 
, Sidgi 
, Ruhillo 
) , in the world, is a rare cognomen. The surname Сидги is habitual in Azerbaijan, where it is quite a rare surname, Sudan, where it is a rare surname, and Bangladesh, where it is a very rare surname. Measured by absolute frequency, it is commonest in Bangladesh, India, and Sudan. Likewise, Сидги is the forename as well as the last name.