• Gelidium J.V. Lamouroux, 1813
• Gelidium abbottiorum R.E.Norris, 1990
• Gelidium acrocarpum Harvey ex Kützing, 1869 accepted as Ceratodictyon repens (Kützing) R.E.Norris, 1987
• Gelidium aculeatum (Greville) Batters
• Gelidium aculeatum Hering, 1846 accepted as Gracilaria aculeata (Hering) Papenfuss, 1967
• Gelidium aculeatum var. abnorme (Greville) Batters
• Gelidium adriaticum C.Perrone, A.Bottalico, G.H.Boo & S.M.Boo, 2019
• Gelidium affine Schiffner
• Gelidium allanii V.J.Chapman, 1969 accepted as Gelidium johnstonii Setchell & N.L.Gardner, 1924
• Gelidium amamiense Tanaka & K.Nozawa, 1965
• Gelidium amansii (J.V.Lamouroux) J.V.Lamouroux, 1813
• Gelidium amansii f. elatum Okamura, 1934
• Gelidium amansii f. elegans (Kützing) Okamura, 1934 accepted as Gelidium elegans Kützing, 1868
• Gelidium amansii f. latius Okamura, 1935
• Gelidium amansii f. teretiusculum Okamura, 1934
• Gelidium ambiguum Piccone & Grunow, 1884
• Gelidium amboniense Hatta & Prud'homme van Reine, 1991
• Gelidium americanum (W.R.Taylor) Santelices, 1976
• Gelidium anthonini J.V.Lamouroux, 1813
• Gelidium applanatum Stegenga, Bolton & R.J.Anderson, 1997
• Gelidium arborescens N.L.Gardner, 1927
• Gelidium arbuscula Bory ex Børgesen, 1927
• Gelidium arenarium Kylin, 1938
• Gelidium asperum (C.Agardh) Greville, 1830
• Gelidium attenuatum (Turner) Thuret, 1892
• Gelidium attenuatum var. confertum (Greville) Batters
• Gelidium australe J.Agardh, 1872
• Gelidium bernabei A.J.K.Millar & D.W.Freshwater, 2005
• Gelidium bipectinatum G.Furnari, 1999 accepted as Gelidium pectinatum (Montagne) Montagne, 1846
• Gelidium biserratum Børgesen, 1943 accepted as Ptilophora biserrata (Børgesen) R.E.Norris, 1987
• Gelidium bornetii Weber-van Bosse, 1926 accepted as Gelidiella bornetii (Weber-van Bosse) Feldmann & G.Hamel, 1934
• Gelidium brasiliense Brunelli, Boo & M.T.Fujii, 2018
• Gelidium bulae Schnetter, 1982
• Gelidium caerulescens Kützing, 1868 accepted as Pterocladiella caerulescens (Kützing) Santelices & Hommersand, 1997
• Gelidium caespitosum Kylin, 1938 accepted as Pterocladiella caespitosa (Kylin) Santelices, 1998
• Gelidium calcicola (Maggs & Guiry) R.E.Norris, 1992 accepted as Gelidiella calcicola Maggs & Guiry, 1988
• Gelidium calidum Jamas, Iha & Fujii, 2017
• Gelidium caloglossoides M.Howe, 1914 accepted as Pterocladiella caloglossoides (M.Howe) Santelices, 1998
• Gelidium canariense (Grunow) Seoane-Camba ex Prud'homme, Haroun & Audiffred, 1994
• Gelidium canariensis (Grunow) Seoane Camba accepted as Gelidium canariense (Grunow) Seoane-Camba ex Prud'homme, Haroun & Audiffred, 1994
• Gelidium cantabricum Seoane-Camba, 1979
• Gelidium capense (S.G.Gmelin) P.C.Silva, 1987
• Gelidium capillaceum (S.G.Gmelin) Meneghini, 1854 accepted as Pterocladiella capillacea (S.G.Gmelin) Santelices & Hommersand, 1997
• Gelidium capillaceum f. crinitum Hauck, 1883 (uncertain)
• Gelidium carolinianum C.Perrone, D.W.Freshwater, A.Bottalico, G.H.Boo & S.M.Boo, 2019
• Gelidium cartilagineum (Linnaeus) Gaillon, 1828 accepted as Plocamium cartilagineum (Linnaeus) P.S.Dixon, 1967
• Gelidium cartilagineum var. canariense Grunow, 1884 accepted as Gelidium canariense (Grunow) Seoane-Camba ex Prud'homme, Haroun & Audiffred, 1994
• Gelidium cartilagineum var. robustum N.L.Gardner, 1927 accepted as Gelidium robustum (N.L.Gardner) Hollenberg & I.A.Abbott, 1965
• Gelidium cartilagineum var. setaceum (C.Agardh) Grunow, 1867
• Gelidium caulacantheum J.Agardh, 1876
• Gelidium ceramoides Levring, 1949 accepted as Zuccarelloa ceramoides (Levring) D'Archino & W.A.Nelson, 2017
• Gelidium chilense (Montagne) Santelices & Montalva, 1983
• Gelidium chungii Setchell & N.L.Gardner, 1935 accepted as Gelidium vagum Okamura, 1934
• Gelidium clavatum (J.V.Lamouroux) J.V.Lamouroux, 1813
• Gelidium clavatum Okamura, 1934 accepted as Gelidium kintaroi Yamada, 1941
• Gelidium claviferum Kützing, 1849
• Gelidium coarctatum Kützing, 1868 accepted as Gelidium capense (S.G.Gmelin) P.C.Silva, 1987
• Gelidium compositum Kützing, 1868 accepted as Nizymenia australis Sonder, 1855
• Gelidium concinnum Baardseth, 1941
• Gelidium congestum W.R.Taylor, 1947
• Gelidium constrictum (Turner) Kützing, 1849 accepted as Polyopes constrictus (Turner) J.Agardh, 1851
• Gelidium contortum N.H.Loomis, 1960 accepted as Gelidium purpurascens N.L.Gardner, 1927
• Gelidium coreanum K.M.Kim, I.K.Hwang, H.S.Yoon & S.M.Boo, 2012
• Gelidium corneum (Hudson) J.V.Lamouroux, 1813
• Gelidium corneum f. clavatum Ardissone, 1874 accepted as Pterocladiella capillacea (S.G.Gmelin) Santelices & Hommersand, 1997
• Gelidium corneum var. abnorme Greville
• Gelidium corneum var. aculeatum Greville
• Gelidium corneum var. caespitosum (Turner) J.Agardh, 1851
• Gelidium corneum var. capillaceum (S.G.Gmelin) Greville, 1830 accepted as Pterocladiella capillacea (S.G.Gmelin) Santelices & Hommersand, 1997
• Gelidium corneum var. clavatum (Lamouroux) Greville, 1830 accepted as Gelidium clavatum (J.V.Lamouroux) J.V.Lamouroux, 1813
• Gelidium corneum var. claviger Greville
• Gelidium corneum var. confertum Greville
• Gelidium corneum var. crinale (Turner) Greville, 1830 accepted as Gelidium crinale (Hare ex Turner) Gaillon, 1828
• Gelidium corneum var. flexuosum Harvey
• Gelidium corneum var. hystrix J.Agardh, 1851 accepted as Gelidium spinosum var. hystrix (J.Agardh) G.Furnari, 1997
• Gelidium corneum var. laciniatum Kützing
• Gelidium corneum var. latifolium Greville, 1830 accepted as Gelidium spinosum (S.G.Gmelin) P.C.Silva, 1996
• Gelidium corneum var. lepadicola Postels & Ruprecht, 1840
• Gelidium corneum var. pectinatum Ardissone & Strafforello, 1883 accepted as Gelidium serra (S.G.Gmelin) E.Taskin & M.J.Wynne, 2013
• Gelidium corneum var. pinnatum (Hudson) Turner
• Gelidium corneum var. pulchellum (Turner) Greville, 1830 accepted as Gelidium pulchellum (Turner) Kützing, 1868
• Gelidium corneum var. ramellolsum (Kützing) Harvey, 1863 accepted as Huismaniella ramellosa (Kützing) G.H.Boo & S.M.Boo, 2016
• Gelidium corneum var. setaceum (Turner) Montagne, 1846 accepted as Gelidiella acerosa (Forsskål) Feldmann & Hamel, 1934
• Gelidium corneum var. setaceum J.V.Lamouroux, 1822 accepted as Gelidium serra (S.G.Gmelin) E.Taskin & M.J.Wynne, 2013
• Gelidium corneum var. simplex Postels & Ruprecht, 1840
• Gelidium corneum var. spinulosum (C.Agardh) Montagne, 1840 (uncertain)
• Gelidium corneum var. subrigidum Grunow, 1867
• Gelidium coronadense E.Y.Dawson, 1953
• Gelidium corrigerum J.V.Lamouroux, 1813
• Gelidium coulteri Harvey, 1853
• Gelidium crinale (Hare ex Turner) Gaillon, 1828
• Gelidium crinale f. latifolium Okamura, 1923
• Gelidium crinale f. luxurians Collins, 1903 accepted as Pterocladiella luxurians (Collins) Boo & Miller, 2016
• Gelidium crinale subsp. longipes (J. Agardh) W.A.Nelson & G.H.Boo, 2014
• Gelidium crinale var. corymbosum (Kützing) Feldmann & G.Hamel, 1936 (uncertain)
• Gelidium crinale var. lubricum (Kützing) Hauck, 1883 accepted as Gelidiella lubrica (Kützing) Feldmann & Hamel, 1934
• Gelidium crinale var. luxurians (Collins) Collins ex N.L.Gardner, 1927 accepted as Pterocladiella luxurians (Collins) Boo & Miller, 2016
• Gelidium crinale var. perpusillum Piccone & Grunow, 1884
• Gelidium crinale var. platycladum W.R.Taylor, 1943
• Gelidium crinale var. polycladum (Kützing) Hauck