Philippi is 15 km north-west of Kavala, which is the natural base. The drive is twenty minutes; Astiko/KTEL local buses from Kavala's central terminal to the village of Krinides (the modern settlement next to the archaeological site) run every hour or so on weekdays, fewer on weekends. From the bus stop in Krinides, it is a five-minute walk to the site entrance.
By car from Thessaloniki, the drive is about two hours on the E90 motorway — Philippi is straightforward as a day trip if you have wheels. There is parking at the site entrance.
The nearest airport is Kavala Megas Alexandros (KVA), about 25 km north — well connected to Athens and to several European cities in summer.