Acacesia is a genus of orb-weaver spiders first described by Eugène Simon in 1895. It contains six species with a mostly neotropical distribution, ranging from South America to Mexico. One species, A. hamata, is found in the US as well.

 The backs of spiders in this genus are marked with a dagger shape, outlined in black and surrounded by a triangular folium. On each side of the dagger there are parallel rows of orange-brown dots. Body length of females ranges from , of males from

Behavior: As the other species are only known from museum specimens, only the natural history A. hamata is known in any detail.

Relationships: Ocrepeira and Cyclosa are close relatives of this genus.

Species: , this genus includes six species:

• Acacesia benigna Glueck, 1994 – Peru, Bolivia, Brazil
• Acacesia graciosa Lise & Braul, 1996 – Brazil
• Acacesia hamata (Hentz, 1847) – USA to Argentina
• Acacesia tenella (L. Koch, 1871) – Mexico to Brazil, French Guiana, Guyana
• Acacesia villalobosi Glueck, 1994 – Brazil
• Acacesia yacuiensis Glueck, 1994 – Brazil, Argentina