[1][2][3][4] It is in the Saint Lawrence River drainage basin, is a right tributary of the Ottawa River, and lies entirely within Jocko Rivers Provincial Park.

[5][6] The Jocko River begins at Jocko Lake in geographic Osborne Township;[2][7] the dispersed rural community of Jocko, on the Ontario Northland Railway, is at the head of the lake.

The river heads northeast, then turns southeast, a course it thereafter follows all the way to its mouth.

The Jocko River passes through geographic Garrow Township[8] and geographic Clarkson Township[9] before entering geographic Jocko Township,[10] where it flows under Ontario Highway 63.

It passes into geographic Eddy Township,[11] takes in the right tributary Little Jocko River, and reaches its mouth at the Ottawa River.