Hicklingia is a genus of extinct plants of the Middle Devonian (around 393 to 382 million years ago).

[1] Initially the genus was placed in the "rhyniophytes", but this group is defined as having terminal sporangia (spore-forming organs), and later work showed that the sporangia of Hicklingia were lateral rather than strictly terminal, so that it is now regarded as having affinities with the zosterophylls.

[2] The sporophyte had a tufted growth habit, with narrow leafless stems (axes) up to 17 cm high which branched dichotomously.

The affinity with zosterophylls is recognized in the cladogram published in 2004 by Crane et al. in which Hicklingia is placed as a sister to all the other lycophytes (living and extinct clubmosses and relatives).

[4] † Hicklingia Adoketophyton, Discalis, Distichophytum (=Rebuchia), Gumuia, Huia, Zosterophyllum myretonianum, Z. llanoveranum, Z. fertile Zosterophyllum divaricatum, Tarella, Oricilla, Gosslingia, Hsua, Thrinkophyton, Protobarinophyton, Barinophyton obscurum, B. citrulliforme, Sawdonia, Deheubarthia, Konioria, Anisophyton, Serrulacaulis, Crenaticaulis Nothia, Zosterophyllum deciduum extant and extinct members Hao and Xue in 2013 listed the genus as a zosterophyll.