According to available geographical data, the longest distance between two cities in Saudi Arabia is between Duba and Tabuk, spanning approximately 2,294 kilometers.
Both cities are located in the northwestern Tabuk Province. Duba sits on the Red Sea coast, while Tabuk lies inland. This distance reflects the vast east-west expanse of the province rather than the country's overall north-south extent. For reference, Saudi Arabia's total north-south distance exceeds 2,000 km, but the Duba–Tabuk route represents the longest measured city-to-city distance within a single province.
Travelers should note that actual driving distances may vary based on the specific route taken.