Cú Chongelt mac Con Mella (died 724?) was a king of the Uí Cheinnselaig

Uí Cheinnselaig

The Uí Ceinnselaig , from the Old Irish "grandsons of Cennsalach", are an Irish dynasty of Leinster who trace their descent from Énnae Cennsalach, a supposed contemporary of Niall of the Nine Hostages...

 of South Leinster

Leinster

Leinster is one of the Provinces of Ireland situated in the east of Ireland. It comprises the ancient Kingdoms of Mide, Osraige and Leinster. Following the Norman invasion of Ireland, the historic fifths of Leinster and Mide gradually merged, mainly due to the impact of the Pale, which straddled...

 or Laigin Desgabair. He was of the Sil Máeluidir sept of this branch of the Laigin, who were found in the later baronies of Shelmalier on the lower reaches of the Slaney River in southern modern County Wexford.

His last paternal ancestor to hold the kingship was Éogan Cáech mac Nath Í who would have lived in the early 6th century of whom Cú Chongelt was a 5th generation descendant.