Goodenia potamica is a prostrate to ascending herb with stems up to long. The leaves on the stems are elliptic to oblong, mostly long and wide, sometimes with a large lobe on one side, near the base. The flowers are arranged in racemes up to long, each flower on a pedicel long with leaf-like bracts. The sepals are oblong, long, the petals yellow and long. The lowerlobes of the corolla are long with wings wide. Flowering mainly occurs around June and the fruit is an elliptic to sphericalcapsule about long.