Réserve naturelle nationale du lac Luitel, National nature reserve with peat bog in Séchilienne, France.

Réserve naturelle nationale du lac Luitel is a protected nature reserve featuring peat bogs and floating vegetation islands in the French Alps. Located at about 1,260 meters (4,130 feet) elevation, it combines open water with partially forested wetland habitat.

The lake fills a depression carved by the Romanche glacier, and its open water is shrinking as sphagnum rafts advance and floating soil lets trees take root. The site was classified by ministerial decree on 15 March 1961, the first national nature reserve in France, under André Malraux. A decree of 3 April 1991 abrogated that decree and renewed the classification; the Luitel peat bogs joined the Natura 2000 network in 1998.

The lake's name, Luitel, is used for the site's two bog systems: the lake-bog with its floating rafts of vegetation and the col bog, partly wooded with mountain pines. The reserve is managed by the ONF of Isère, which organises regular outings and keeps the bog open by cutting trees unsuited to the habitat.

The reserve lies in a depression beside the access road to Chamrousse, at 1,260 m between Uriage-les-Bains and the ski resort, and is crossed by marked footpaths. The ONF manages the site and organises regular outings; hunting, fishing and farming are banned throughout. Salt spread on the two nearby departmental roads in winter, about one tonne per kilometre, has disturbed the bog's water chemistry, and work in 2012 channelled the salty runoff.

The lake's water appears black because its acidity keeps organic matter in suspension instead of letting it settle. The reserve also shelters relict glacial species such as inundated clubmoss, marsh scheuchzeria, round-leaved sundew and lesser bladderwort.