Adelaide United On 22 September 2017, Stamatelopoulos signed a 2-year scholarship contract with
Adelaide United. In his fourth senior appearance for the club, he scored his first
A-League goal off the bench to equalise in an away match against
Western Sydney Wanderers on 10 January 2018.
Western United On 20 March 2019, it was announced that Stamatelopoulos had signed for new
A-League club
Western United. On 25 January 2021, the club announced that Stamatelopoulos had departed.
Newcastle Jets A few days after leaving
Western United, it was announced Stamatelopoulos would join
Newcastle Jets when the transfer window opens on 16 February. Stamatelopoulos made his debut for the Jets as a substitute in a loss to
Wellington on 28 February. In July 2023 Stamatelopoulos returned to Newcastle Jets on two year deal.
Motherwell On 30 July 2024,
Scottish Premiership club
Motherwell announced the signing of Stamatelopoulos from
Newcastle Jets for an undisclosed fee, on a contract until 2027.
Loan to Sydney FC On 10 February 2026, Stamatelopoulos returned to Australia joining
Sydney FC on loan for the remainder of the
2025–26 season, with the club having a purchase option to make the deal permanent. His debut for the club came three days later against former side
Adelaide United. On 7 March 2026, Stamatelopoulos would score his first goal for the club against
Big Blue rivals
Melbourne Victory. ==International career==