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The work explores the phase transformation sequence and the kinetics of ω formation in a novel metastable β titanium alloy of Ti–3Al–5Mo–7V–3Cr (wt%) through dilatometer test and phase/microstructure characterizations. The phase transformation sequence has been identified as β → β + ω, β + ω → α + β, β → β + α, and α → β during the continuous heating. The formation of ω phase has underwent nucleation and growth stages revealed by the S-shaped kinetic curve. The diffusion controlled mechanism has been analyzed via Avrami exponent. The average activation energy for β → β + ω phase transformation has been evaluated 90.42 kJ/mol via Kissinger–Akahira–Sunose equation. The activation energy difference between early and late stages of ω formation has been compared among metastable β titanium alloys. The small value of Ti-3573 alloy may imply a thermo-kinetic inconvenience of ω assisted α formation.