Ulusoy was born in Istanbul, Turkey. His father is of Turkish descent from Bulgaria. His father immigrated to Turkey when he was 10 years old. He has a younger brother named Atalay. After graduating from high school, Ulusoy first started studying at the Istanbul University's Department of Garden Design and Landscaping. Cagatay Ulusoy was a hyperactive kid. His parents put him in sports at an early age to utilise his energy to maximum. He dreamt of being a basketball player for nine years. He was also good at swimming and diving. As a student, he then started to work as a model at the age of 19. In 2010, he won a modelling contest in Turkey and was named Best Model of Turkey. On the same night that he was named Best Model of the Year, he received his first acting job offer for the TV series Adini Feriha Koydum. In 2011 he shot his first movie Anadolu Kartallari, in a supporting role. Earlier in the same year, Ulusoy starred in the TV series Adını Feriha Koydum as the lead playing Emir Sarrafoğlu. While the first two seasons of the series were successful, the third season that aired under another title Emir'in Yolu (Emir's way), was less successful and due to low ratings, it was cancelled after a few episodes in 2012. This was mainly due to the fact that Ulusoy’s co-star Hazal Kaya was not in the third season.Adını Feriha Koydum was later sold and aired in various countries such as Ukraine, Pakistan, Iran, Serbia, Peru, India.