The State Highways of the Republic of Turkey (Turkish: Türkiye Cumhuriyeti Devlet Yolları) are an integrated network of highways and roads in Turkey, consisting of a numbered grid spanning across the country.

In the early 21st century, the network was greatly expanded to accommodate four-lane highways throughout the country.

[1] Unlike motorways in Turkey, state highways do not have a minimum design standard.

All state highways have a three-digit designation preceded by a D. The system is numbered based on direction and location.

For east-west roads, routes in the north will have lower numbers that get higher towards the south.