Anelosimus nelsoni is a species of spider in the family Theridiidae.

It is only known from iSimangaliso Wetland Park, KwaZulu-Natal, South Africa.

The male holotype specimen is 2.08 millimetres (0.082 in) in length, and the female paratype is 2.60 millimetres (0.102 in) in length.

Both the holotype and paratype were found on Fanies Island, 5 km south of Cape Vidal.

Both were collected from bushes or trees in an open forest patch.