Regen is a Landkreis (district) in Bavaria, Germany.

It is bounded by (from the south and clockwise) the districts of Freyung-Grafenau, Deggendorf, Straubing-Bogen and Cham, and by the Czech Republic (Plzeň Region).

The district was established in 1972 by merging the former districts of Regen and Viechtach.

The district is entirely located in the Bavarian Forest.

The coat of arms displays: