If you’re flying you’ll arrive at Thessaloniki Airport Makedonia (not to be confused with the country North Macedonia), the second largest airport in Greece. The airport is located 14 km outside the city center and you can take a public bus (€2) that will take you 40 – 50 min and runs every 30 min or a taxi (€20).
There are a few train routes including international travel from Sofia (Bulgaria), Skopje (North Macedonia) and Belgrade (Serbia) as well as from Athens.
The bus station serves 800 daily routes including 5 international (Germany, Bulgaria, Albania, Czechia and Slovakia) and hundreds of domestic departures (and arrivals). It is not nearby the center but easily reached by taxi or public transit.
There is also the option to come by sea but only when arriving with a cruise. The port is well connected to the rest of the city.
When you’re here it is easy to get around on foot.