The Oldenburg or Oldenburger is a warmblood horse from the north-western corner of Lower Saxony, what was formerly the Grand Duchy of Oldenburg. The breed was built on a mare base of all-purpose farm and carriage horses, today called the Alt-Oldenburger. The modern Oldenburg is managed by the Association of Breeders of the Oldenburger Horse, which enacts strict selection of breeding stock to ensure that each generation is better than the last. Oldenburgers are tall sport horses with excellent gaits and jumping ability. The breeding of Oldenburg horses is characterized by very liberal pedigree requirements and the exclusive use of privately owned stallions rather than restriction to a state-owned stud farm.

Warmbloods are a group of middle-weight horse types and breeds primarily originating in Europe and registered with organizations that are characterized by open studbook policy, studbook selection, and the aim of breeding for equestrian sport. The term distinguishes these horses from both heavy draft horses and refined light saddle horses such as the Thoroughbred, Arabian, and Akhal-Teke. Although modern warmbloods are descended from heavier agricultural types systematically upgraded by hotblood influence, the term does not imply that warmbloods are direct crosses of "cold" and "hot".