Syllepte attenualis is a moth in the family Crambidae. It was described by George Hampson in 1912.[1] It is endemic to Kenya.[2]
The wingspan is about for males and for females. The forewings are pale ochreous, irrorated with brown, especially on the costal area to the postmedial line. There is a subbasal black spot on the inner margin and an oblique sinuous fuscous antemedial line, as well as a black point in the middle of the cell and a discoidal bar. The postmedial line is fuscous and there is a punctiform black terminal line. The hindwings are pale ochreous, irrorated with brown especially on the disc. There is a slight fuscous discoidal bar and a fuscous postmedial line. There is also a fine black terminal line.[3]