The Kuinder of Tjonger is a former river in the Netherlands, now functioning as a managed waterway in the Frisian/Overijssel border region. It forms part of a well-established 29-kilometer round-trip kayak route that also takes in the Linde and Scheene waterways, with Ossenzijl serving as the recommended starting point.

From Ossenzijl, paddlers head right onto the Linde for approximately 8 kilometers before reaching the locks at Kuinre. When the locks are staffed and operational, passage is free of charge; if unstaffed, a portage of roughly 100 meters under a bridge is required. The lock sides are not excessively high, though there are no dedicated kayak piers at this point. After passing through the Kuinre locks, the route turns right onto the former Tjonger, covering 4.9 kilometers to the former locks at Schoterzijl. There is a small marina at Schoterzijl, but again no kayak pier, and the sides are described as rather high — mooring can be difficult if spaces are taken. A pier is available nearby, along with snackbar Snackservice De Jong and Restaurant Snoek.

A short distance further, the route reaches the locks connecting to the Scheene. These locks are no longer in use but have good kayak piers, a picnic table, and a teagarden at the mill De Rietvink. The Scheene section heads south, requiring paddlers to carry their kayak across a road at one point before finding a kayak pier on the other side. The route involves some navigation through narrow passages in water plants and requires attention to junctions. There are three portages in total on the full loop, reduced to one if the Kuinre locks are operational.

Kayak rentals are available locally through De Kluft in Ossenzijl and Kayak Tjonger Tours in Langelille. The waterway passes through flat, open landscape typical of this part of the Netherlands, and there is an archaeological site of note in the broader area near the Tjonger and Linde confluence toward the Ossenzijlersloot.