René-François Walter de Sluse (French: [də slyz]; also Renatius Franciscus Slusius or Walther de Sluze; 2 July 1622 – 19 March 1685) was a Walloon mathematician and churchman who served as the canon of Liège and abbot of Amay.

He and Johannes Hudde found algebraic algorithms for finding tangents, minima and maxima that were later utilized by Isaac Newton.

The rule is precisely that of Newton... To have given this would have shown the world that the grand communication which was asserted to have been sent to Leibniz in June 1676 might have been seen in print, and learned from Sluse, at any time in the previous years: accordingly it was buried under reference.

[3] He found for the subtangent of a curve an expression equivalent to He also wrote numerous tracts, and in particular discussed at some length spirals and points of inflexion.

Several of his works were included in the Transactions of the Royal Society, e.g. his method of drawing tangents to geometrical curves.