Lake Nobelius is a small lake within Emerald Lake Park, part of the Emerald Lake Precinct in the southern Dandenong Ranges, Victoria.

Along with the larger Lake Treganowan, it is fed by Wattle Creek and sits at the eastern end of the park among heritage landscapes, ornamental trees, and established recreational facilities.

A wheelchair- and pram-friendly loop walk encircles Lake Nobelius, connecting to the broader path network that links the two lakes and extends toward Nobelius Heritage Park. Swimming is not permitted in the lake at any time.