The Ringvaart, formally known as the Ringvaart of the Haarlemmermeer Polder, is a circular canal in the province of North Holland. True to its name — "ring canal" in Dutch — it forms a complete loop around the Haarlemmermeer polder, tracing the boundary of the Haarlemmermeer municipality. The canal stretches 61 kilometres in total length and reaches a depth of 2.4 metres, enclosing an area of more than 180 square kilometres.

Construction began in 1839, when thousands of laborers dug the canal through existing land, following as closely as possible the contour of the former Haarlemmermeer lake. At three locations — Vijfhuizen, Lisserbroek, and Huigsloot — the canal was cut through peninsulas, which subsequently became part of the Haarlemmermeer polder. The canal was completed in 1845 and used to drain the lake, a major feat of Dutch water engineering. The canal and the surrounding polder are recognized as a UNESCO World Heritage Site.

The Ringvaart carries both commercial and recreational boat traffic, so paddlers should be prepared to share the water with larger vessels. A portion of the canal forms part of a designated sail route connecting Hollands Diep to the IJsselmeer, and this section is navigable for ships with masts exceeding 6 metres in height, indicating meaningful vessel traffic on at least part of the route.

One notable feature along the canal is a aqueduct near Roelofarendsveen, where the Ringvaart passes beneath the A4 motorway. Built in 1961, it is the oldest aqueduct in the Netherlands. A newer, expanded aqueduct completed in 2006 extends 1.8 kilometres and also accommodates the HSL-Zuid high-speed railway crossing, making this stretch a structurally distinctive section of the route.

The canal's circular geometry makes it well suited to multi-day circumnavigation trips, with the full 61-kilometre loop offering a consistent, low-gradient waterway through the flat Dutch polder landscape. Fishing reports indicate the presence of European perch, northern pike, and zander in the canal.