Quasilinear may refer to:
Quasilinear function, a function that is both quasiconvex and quasiconcave Quasilinear utility, an economic utility function linear in one argument In complexity theory and mathematics, quasilinear time O(n (log n)k), or sometimes more specifically O(n log n) Quasilinear equation, a type of differential equation; see Partial differential equation#Linear and nonlinear equations Quasi linear convective system, a line of thunderstorms, often along or ahead of a cold front