The Croatia midfielder will complete the formalities of the move when he returns from the World Cup and he could not hide his delight at the pending transfer.
The 26-year-old midfielder expressed his excitement at the switch as he continued his World Cup preparations with Croatia at their training base in Praia de Bahia.
"I am very happy. It is a dream come true," he told Catalan paper Sport.
Barca agreed to meet Sevilla's €20million (£16.1m) asking price to make the Rakitic the first signing since Luis Enrique replaced Tata Martino as head coach at the Nou Camp.
It is widely reported in Spain that Rakitic's impending move will result in Cesc Fabregas sealing a return to the Premier League, with Chelsea favourites to land his signature.