S. flavescens may refer to:
Salix flavescens, a willow native to western North America Scarus flavescens, a parrotfish native to the Atlantic Ocean Sesamia flavescens, an owlet moth Setophaga flavescens, a bird endemic to the Bahamas Silaus flavescens, a perennial plant Silene flavescens, a flowering plant Sitona flavescens, a broad-nosed weevil Solmaris flavescens, a jellyfish with a dome-shaped bell Sophora flavescens, a plant used in traditional Chinese medicine Staphylinus flavescens, a rove beetle Stathmopoda flavescens, a concealer moth Stenaroa flavescens, an owlet moth Stenospermation flavescens, a flowering plant Stigmella flavescens, a Turkmen moth Streptostyla flavescens, a land snail Styposis flavescens, a New World spider Syngnathus flavescens, a seaweed pipefish