Jatuncocha (possibly from Quechua hatun (in Bolivia always jatun) big, large qucha lake, "big lake") is a lake in the Cordillera Blanca in the Andes of Peru located in the Ancash Region, Huaylas Province, Santa Cruz District. It is situated at a height of comprising an area of . Jatunccocha lies in the Santa Cruz gorge between the peaks of Quitaraju in the north and Caraz in the south, northeast of a smaller lake named Ichiccocha (Quechua for "little lake").
The Santa Cruz Creek flows through the lake. It is a right tributary of the Santa River.