With the reduction in extent of Arctic Ocean sea ice in recent years, commercial use of Arctic Sea shipping routes has attracted increasing attention. An urgent task for promoting the use of safe and cost-efficient routes in the Arctic Sea is the construction of a navigation support system. Such a system is essential not only for monitoring and forecasting the extent of sea ice but also for integrating such information in determination of the optimal route. This research developed an Arctic Sea Route Search System that has been published as a web application on the Arctic Data archive System website. Ship speed is calculated based on an approximate expression of actual Automatic Identification System data and an Ice Index, which is an index that reflects the ease of navigation based on ice type and the ship’s ice class. The A* algorithm searches for the optimal route using a search graph that places nodes at the grid positions of input data. Comparison of several test calculations using different parameters confirmed that the route search system provides reasonable results.