Linanthus is a genus of annual and perennial plants in the phlox family Polemoniaceae.
The species are found in western North America and in Chile, with the greatest diversity in California.
The stems are erect, with multiple branches arising directly from the base, and grow 2–15 cm tall. The leaves are stem-like (cauline) and opposite, with shapes ranging from entire to palmately lobed, the 3-9 lobes being linear to lanceolate or spatulate. Flowers have a tubular calyx, and the corolla may be funnel- or bell-shaped, or .
The genus name is from the Greek for "flax flower", since the flowers superficially resemble those of flax. The genus has recently been split, with many of the species formerly included now transferred to the genus Leptosiphon (Jepson Manual).
26 species are accepted.