A polysiloxane-based macromonomer for an ophthalmic lens, which exhibits excellent compatibility with respect to a hydrophilic component such as a hydrophilic monomer. The polysiloxane-based macromonomer has at least one polymerizable group, a polysiloxane chain having a siloxane unit as a repeating unit, a polyoxyethylene chain in which a number of repetition of an oxyethylene group is two or more, and a polyoxyalkylene chain having an oxyalkylene group other than the oxyethylene group as a repeating unit, wherein an HLB value calculated according to a formula: [HLB value] = E/5 is within a range from 0.7 to 6.0, wherein E represents a weight fraction (wt%) of the oxyethylene group in a molecule of the polyxiloxane-based macromonomer.