<p>Thermodynamic property data for solid neon have been analyzed to construct a new fundamental equation of state (EOS) expressed in terms of the Helmholtz energy. The formulation follows the quasi-harmonic Debye–Grüneisen framework and adopts the same Helmholtz energy structure as that used for solid argon, consistent with the general strategy previously developed for solid CO₂, benzene, and argon. The solid EOS is thermodynamically coupled to a reference fluid EOS along the sublimation and melting curves, enabling consistent calculations of solid–fluid phase equilibrium as well as single-phase solid properties up to 328&#xa0;K and 5800&#xa0;MPa. Model parameters were obtained by regression to a comprehensive literature dataset including cell volume, isobaric heat capacity, thermal expansivity, isothermal and isentropic bulk modulus, phase-equilibrium pressure, and phase-transition enthalpy. Within its intended range of application, the EOS reproduces fitted molar volumes typically within about 0.1&#xa0;% along the sublimation curve and 0.5&#xa0;% along both the melting curve and in the compressed solid. Heat capacity and thermal expansivity are represented with uncertainties of approximately 3&#xa0;% to 10&#xa0;% depending on temperature. Isothermal and isentropic bulk modulus are described to within about 3&#xa0;% and 4&#xa0;%, respectively, while sublimation and melting pressures are represented within approximately 2&#xa0;% and 5&#xa0;%. Overall, the new Helmholtz energy EOS provides a compact and internally consistent representation of solid neon thermodynamic properties suitable for cryogenic and high-pressure applications.</p>