Nemeth made his debut in a senior game on 20 April 2018, when he appeared as a starting player for the second team of his club
SV Mattersburg in the
Landesliga Burgenland, the fourth highest division of Austrian football. Mattersburg II finished the season in first place and was promoted to the
Regionalliga Ost. In December 2018, he was included in the Mattersburg first team squad for the first time, but did not make an appearance. He debuted for the first team in the
Austrian Bundesliga in May 2019, when he started against
Wacker Innsbruck on the last matchday of the 2018–19 season. In the 2019–20 season, Nemeth played for both the first and second team of Mattersburg. The club declared bankruptcy at the end of the season and became defunct. Nemeth then moved to Germany in September 2020 and joined
Mainz 05, where he signed a contract until June 2024. After making two appearances for the second team in the
Regionalliga Südwest (fourth tier), he returned to Austria in October 2020 and went on loan to
Sturm Graz for the rest of the season. By the end of his loan, he had made 28 appearances in the Austrian Bundesliga, scoring two goals. After eight appearances until October 2023, he missed the rest of the season due to an injury. In the
2023–24 season, he won the 2. Bundesliga title and was promoted to the Bundesliga with St. Pauli. ==International career==