Ilulissat is small enough to walk everywhere. The town center, the harbor, the museum quarter, and the trailhead for the icefjord paths are all within comfortable walking distance of each other. There are no public buses.
Taxis are available and cheap by European or North American standards — useful for reaching the Icefjord Centre quickly or getting back from the airport. Most tour operators will pick you up from your accommodation.
In winter, snowmobiles are a common form of local transport, and dog sled tours typically depart from a meeting point just outside town. In summer, boats from the harbor are the main way to access outlying areas.