Cuevas, an Under-20 international, is currently with O'Higgins in the Chilean domestic league, but he said he will head for Stamford Bridge in June.
"I am very happy. It's all gone through very quickly. It was sealed this week and I'll be off in the middle of the year. Chelsea have been after me for more than a year," Cuevas told Radio Cooperativa, with the 17-year-old adding he had been hoping the move would come about.
Chelsea have reportedly handed the youngster a four-year contract.
