Frederick I, Count of Rietberg

Frederick I, Count of Rietberg (died 5 July 1282), was the eldest son of Count Conrad I and Oda of Lippe. He married Beatrix of Horstmar. In 1264 his father, by then a Teutonic Knight, made the county over to him.

In 1267 Frederick fought for Archbishop Engelbert II of Cologne at the battle of Zülpich, was captured by Bishop Gerard of Münster, and spent a year and a half in prison. He died in 1282 and was buried at Marienfeld Abbey, succeeded by his son Conrad II.