Suillus salmonicolor, commonly known as the Slippery Jill, is a fungus in the family Suillaceae of the order Boletales. First described as a member of the genus Boletus in 1874, the species acquired several synonyms, including Suillus pinorigidus and Suillus subluteus, before it was assigned its current binomial name in 1983. It has not been determined with certainty whether S. salmonicolor is distinct from the species S. cothurnatus, described by Rolf Singer in 1945.

The mushroom's dingy yellow to brownish cap is rounded to flattened in shape, slimy when wet, and grows up to 8 cm (3 in) wide. The small pores on the underside of the cap are yellow before becoming olive-brown. The stem is up to 10 cm (4 in) long and 1.6 cm (3⁄4 in) thick and is covered with reddish-brown glandular dots. Young specimens are covered with a grayish, slimy partial veil that later ruptures and leaves a sheathlike ring on the stem. Other similar Suillus species include S. acidus, S. subalutaceus, and S. intermedius.

S. salmonicolor is a mycorrhizal fungus—meaning it forms a symbiotic association with the roots of plants such that both organisms benefit from the exchange of nutrients. This symbiosis occurs with various species of pine, and the fruit bodies (or mushrooms) of the fungus appear scattered or in groups on the ground near the trees. The fungus is found in North America, Hawaii, Asia, the Caribbean, South Africa, Australia and Central America. It has been introduced to several of those locations via transplanted trees. Although the mushroom is generally considered edible—especially if the slimy cap cuticle and partial veil are first peeled off—opinions about flavor vary.