The 17-year-old, who has been linked with Arsenal, Manchester City and Tottenham, has confirmed he is to join the Spanish champions
Reports in Croatian and Spanish media on Thursday had suggested Barcelona were closing in on a deal for Halilovic, before the player posted confirmation via his own social media account early on Friday morning.
The 17-year-old midfielder posted a picture on his Instagram account with the caption: "Thanks Dinamo Zagreb for everything!! My first club and biggest love!! Now is time to move on to Barcelona.”
Halilovic has been touted as one of Europe’s brightest emerging talents, with Arsenal, Manchester City and Tottenham all linked with a move over the last 18 months.
The midfielder, who has already been capped three times by Croatia at senior level, broke into Dinamo’s first team last season and also made three brief Champions League appearances as a late substitute.
Halilovic scored his first two league goals this season in a 2-2 draw against Rijeka on Wednesday.
Earlier this week, Dinamo president Mirko Barisic revealed the Catalans were leading negotiations over a move for Halilovic, who he expects will have to work his way up the ranks to the first team.
"Executive chairman Zdravko Mamic is in contact with Barcelona representatives," Barisic told Jutarnji List. "We at Dinamo want all parties to be satisfied with this transfer.
"Nobody has any guarantee when it comes to the first team of Barcelona. But surely he must safely play in the second [B] team."