The Todd River is an ephemeral river in the southern Northern Territory of central Australia, originating in the MacDonnell Ranges and flowing southeast approximately 320 kilometres before disappearing into the Simpson Desert, where it eventually becomes a tributary of the Hale River and drains into Lake Eyre in South Australia. The river passes through Alice Springs, running along the edge of the central business district and through Heavitree Gap. Its basin covers 445 square kilometres.

The defining characteristic of the Todd for paddlers is its extreme rarity of flow. The river runs dry or near-dry approximately 95% of the year, making it one of the most infrequently paddleable rivers in Australia. When heavy rainfall occurs in the catchment north of Alice Springs, the river can begin flowing through town roughly 6 to 8 hours later. The transition from dry sandy bed to bank-to-bank flow can occur within 15 minutes, and in significant events the river will break its banks entirely, cutting off road and rail access to Alice Springs.

When the Todd does flow, it takes on the characteristics of a flood-stage inland river, with all the associated hazards. Paddling is recommended only for experienced whitewater kayakers using fully outfitted whitewater boats and appropriate safety gear. Attempting the river in other craft during flood conditions has resulted in fatalities. The river north of Alice Springs is noted as a location where locals have paddled during solid flow events.

The Todd holds considerable cultural significance. It is central to the identity of Alice Springs and carries the Arrernte name Lhere Mparntwe. The river was named in 1870 by surveyors for the Overland Telegraph Line after Sir Charles Heavitree Todd, then postmaster general of South Australia. The dry sandy riverbed is also the site of the annual Henley on Todd Regatta, a well-known event in which participants run through bottomless boat frames along the dry river — an event that only gets cancelled in the rare circumstance that the river is actually flowing.

Given the unpredictable and infrequent nature of flow, paddling the Todd cannot be planned in advance in the conventional sense. Opportunities arise opportunistically following significant rainfall events in the catchment area.