Abstract The methanolic extract of the marine sponge Ircinia felix has yielded nine novel fatty acid esters, (7 E , 12 E , 18 R , 20 Z )‐variabilin (5 Z , 9 Z )‐22‐methyltricosadienoate, (7 E , 12 E , 18 R , 20 Z )‐variabilin (5 Z , 9 Z )‐tetracosadienoate, (7 E , 12 E , 18 R , 20 Z )‐variabilin hexadecanoate, (7 E , 12 E , 18 R , 20 Z )‐variabilin 10‐methylhexadecanoate, (7 E , 12 E , 18 R , 20 Z )‐variabilin 15‐methylhexadecanoate, (7 E , 12 E , 18 R , 20 Z )‐variabilin 14‐methylhexadecanoate, (7 E , 12 E , 18 R , 20 Z )‐variabilin 9‐octadecenoate, (7 E , 12 E , 18 R , 20 Z )‐variabilin octadecanoate, and (7 E , 12 E , 18 R , 20 Z )‐variabilin 2,11‐dimethyloctadecanoate, along with the recently described (7 E , 12 E , 18 R , 20 Z )‐variabilin 11‐methyloctadecanoate. The characterization of the new fatty acids (5 Z , 9 Z )‐22‐methyltricosadienoic and 2,11‐dimethyloctadecanoic acids is also described. The chemical structures were determined by extensive spectroscopic, chromatographic, and chemical analyses.