Johannes Jacobus Smith (Antwerp 29 June 1867 – Oegstgeest 14 January 1947) (sometimes written as Joannes Jacobus Smith) was a Dutch botanist who, between years 1905 to 1924, crossed the islands of the Dutch East Indies (mainly Java), collecting specimens of plants and describing and cataloguing the flora of these islands. The standard botanical author abbreviation J.J.Sm. is applied to plants described by J.J. Smith.
The description of the flowers of the western half of New Guinea (then a Dutch territory) is largely based on his work. He was, next to Rudolf Schlechter, the most prolific author on New Guinea orchids. He also described numerous plants from other families, such as Ericaceae and Euphorbiaceae.