Christopher I (1219-1259) was king of Denmark between 1252 and 1259. He was the son of Valdemar II of Denmark by his wife, princess Berengaria of Portugal, and was elected King upon the death of his older brother Abel in the summer of 1252.

While trying to have his brother Eric IV of Denmark, who was murdered in 1250, supposedly by king Abel, canonized, Christopher found himself excommunicated from the Catholic church. His men had arrested and humiliated the proud and self-righteous arch bishop Jakob Erlandsen after Erlandsen had refused to recognize Christopher's son Eric as his (Christopher's) successor, but the excommunication had little or no effect, and Christopher was buried in Christian soil by the bishop of Ribe upon his death on May 29th, 1259. Some claimed that the King died very unexpectedly and shortly after taking the holy communion, but proof that he was in fact poisoned have never been offered, although Christopher's allies apparently took to calling him "Krist-Offer" (Christ's sacrifice).

Christopher (Kristoffer) married Margrethe Sambiria of Kassuben and had three children:

• Matilda (died 1311), married to Albert III, margrave of Brandenburg
• Margaret (died 1306), married count John II of Holstein-Kiel
• king Eric V of Denmark.