Loir-et-Cher is a department in the Centre-Val de Loire region of France. Its name is originated from two rivers which cross it, the Loir in its northern part and the Cher in its southern part. Its prefecture is Blois. The INSEE and La Poste gave it the number 41. It had a population of 329,470 in 2019.

Centre-Val de Loire or Centre Region, as it was known until 2015, is one of the eighteen administrative regions of France. It straddles the middle Loire Valley in the interior of the country, with a population of 2,572,853 as of 2018. Its prefecture is Orléans, and its largest city is Tours.