Kastamonu is an electoral district of the Grand National Assembly of Turkey. It elects three members of parliament (deputies) to represent the province of the same name for a four-year term by the D'Hondt method, a party-list proportional representation system.

Population reviews of each electoral district are conducted before each general election, which can lead to certain districts being granted a smaller or greater number of parliamentary seats. At the last election Kastamonu's seat allocation was reduced to three seats after the province was represented by four MPs for twelve years.