The Thick-billed Flowerpecker (Dicaeum agile) is a small passerine bird. It is a resident breeder in tropical southern Asia from India east to Indonesia and Timor.

The Thick-billed Flowerpecker is a common resident breeding bird of forests, other well-wooded habitats and cultivation. Two to four eggs are laid in a purse-like nest suspended from a tree.

This species lacks the brightly coloured male plumage typically shown by flowerpeckers. It is a very small, stout bird, 10cm in length, with a short tail, short thick curved bill and tubular tongue. The latter features reflect the importance of nectar in its diet, although berries, spiders and insects are also taken.

The adult Thick-billed Flowerpecker has olive-green upperparts and greyish white underparts, streaked on the breast.