Born in Zaporizhia, Ukrainian Soviet Socialist Republic, Oliynyk joined Dynamo Kyiv in 2004.

For the first half of the 2008–09 season, Oliynyk was loaned, alongside teammate Vitaliy Mandzyuk, to Arsenal Kyiv in July 2008.

Seeking to strengthen his team for the 2008–09 UEFA Cup, Metalist Kharkiv coach Myron Markevych purchased Oliynyk during the winter transfer season.

In July 2011, Oliynyk changed club to join fellow Premier League side Dnipro Dnipropetrovsk.

He is married, and has a son and a daughter, whose godfather is the famous Ukrainian football player Yevhen Konoplyanka.