Family name Сайенко (Sajenko 
, Сайенко) , all around the world, is a rare last name. The cognomen Сайенко is characteristic of Estonia, where it is quite a rare surname, Croatia, where it is a rare surname, and Lithuania. Not in comparison with a country's population, the name is most common in Poland, Estonia, and Croatia. Very seldom, Сайенко is the forename as well as the last name.