The mechanical behavoiur of Ti-6Al-4V alloy under cyclic load is essential to understand its crashworthiness, especially for aerospace structural applications. The in-house developed extended finite element (XFEM) based MATLAB code was used to model fatigue crack growth rate (FCGR) in direct energy deposited Ti-6Al-4V alloy. The assumed computational domains such as single-edge, center-edge, and dual-edge cracked square specimens, were loaded under the mode-I scenario to assess FCGR behaviour. The novelty of the work is to analyse and predict all three regimes of “da/dN-ΔK” plot, i.e. threshold-, stable-, and catastrophic-crack growth regimes by using NASGRO empirical phenomenological model, unlike only stable-crack regime of Paris model, which is rare in literature. This phenomenological model was analysed based on the maximum cyclic total strain energy release rate (GT), threshold strain energy release rate (GTH), and quasi-static strain energy release rate (GQS) values. The FCGR behaviour of different computational domains, with respect to varying geometrical configurations, were characterized using microstructure-property correlation. The range of stress intensity factor (ΔK) was also compared with respect to different cracked domains, which is extended further for critical case scenarios for the FCGR prediction. © 2023