Hieracium piloselloides is a species of flowering plant in the aster family known by the common name tall hawkweed. It is native to Europe and it is present in North America as an introduced species and a common weed. This is a perennial herb producing erect stems which may exceed one meter in height from a rhizome and root network. The leaves are variable in size and shape. The inflorescence is made up of flower heads containing yellow flowers.