Coset symmetry arises in many systems such as Higgs phases of gauge theories and quantum spin liquids. When the coset is quotient by a non-normal subgroup, coset symmetry becomes a non-invertible symmetry. I will discuss properties of coset non-invertible symmetry and its fractionalization using examples in field theories and lattice models, and comment on the dynamical implication. The talk is based on arXiv: 2405.20401 and work in progress with Ryohei Kobayashi and Carolyn Zhang.