Mohammed Al Mudhabi has been sworn in and he has handed over his credentials as the new envoy, a statement from President Kais Saied said.
The presidency published a video of Mr Al Mudhabi meeting Tunisian Foreign Minister Nabil Ammar as well as Mr Saied, who ordered the appointment of a new ambassador to Damascus earlier this month.
Tunis cut diplomatic ties with Damascus in 2012, as it and other Arab nations shunned Syria over its brutal crackdown on protests and its actions in the ensuing civil war.
In 2015, relations resumed but were limited to a consular office in Damascus that managed Tunisian affairs in the country.
Mr Al Mudhabi previously served as Tunisia's consul general in Munich and as the director of relations with Northern and Central Europe, Russia and the Caucasus, Syrian state media reported.
Tunisia boosted its diplomatic presence in Syria following February's earthquake which devastated much of the northern part of the country as well as southern Turkey.
In a meeting with Mr Ammar, Mr Saied said Syria's problems are an “internal issue” and that ambassadors are appointed to a specific state, not a specific regime.
Mr Said has held several phone calls with his Syrian counterpart Bashar Al Assad, while their respective foreign ministers have also spoken.