On May 25, 2023, it became public that Holger Ehrhardt will receive the European Fairy Tale Prize 2023 - on September 28, 2023, the award ceremony will take place in Volkach. The Walter Kahn Fairy Tale Foundation, which endows the European Fairy Tale Prize with 5000 euros, thus honors "one of the most nationally and internationally renowned Grimm and fairy tale researchers in Germany". Ehrhardt has "helped Grimm research in Germany to achieve the highest reputation, so that his professorship is also perceived internationally as a lighthouse of Grimm research.

Ehrhardt's research is outstanding in the field of editing (Grimm diaries and letters), in the field of indexing new Grimm holdings, and in the field of source and contributor research. His research on the mysterious "Marburg Fairy Tale Woman" became particularly famous: With the discovery of the "Cinderella" narrator, Ehrhardt solved one of the great mysteries of Grimm research.