One of the main models used to study problems of ferromagnetic resonance is the Landau–Lifshitz phenomenological model. According to this model, the dynamics of the magnetization in a ferromagnet is described by a nonlinear Landau–Lifshitz equation. Because of the nonlinearity of this equation the physical properties described by it are extremely diverse. Depending on the physical situation, a system is characterized by soliton or chaotic solutions. Usually it is assumed that a necessary condition for obtaining a chaotic solution is that the system be acted upon by a random field due to fluctuations of the local magnetization. It is shown here that chaotic dynamics can also be obtained in the case of a regular external force. The conditions for the appearance of Hamiltonian chaos are determined, and numerical estimates are made for concrete substances. A kinetic equation describing the dynamics of the magnetization under conditions of stochasticity is obtained. It is shown that the solution of the kinetic equation agrees well with the solutions of the Landau–Lifshitz equation, confirming the applicability of the mathematical description for chaotic dynamical systems.