Born in Clearwater, Florida, Stefanovic moved to Canada at a young age and was raised in Oakville, Ontario.

[1] On June 30, 2023, he signed an official professional contract with Toronto FC II, after having already played 13 games that season as an academy call-up.

[6][7] He became the second-youngest player to appear in an MLS match for Toronto FC (16 years, 10 months and 22 days).

[12] After initially signing as an off-roster player earlier, he would officially join the Toronto FC first team roster for the 2025 season.

[12] Stefanovic is of Serbian descent, born in the United States, and raised in Canada, and eligible for all three nations at international level.