Al–Cu–Mg composites reinforced with sub-micron tungsten carbide (WC) particles were synthesized by powder metallurgy and subjected to T6 heat treatment to clarify the interplay between dispersion strengthening and precipitation hardening. Composites with 1–3 wt.% WC (average size 0.8 μm) were solution-treated at 540 °C for 3 h, water-quenched, and aged at 195 °C for up to 100 h. Microstructural analyses confirmed a uniform distribution of WC and demonstrated that its presence did not modify the dissolution–precipitation sequence of the Al-Cu-Mg matrix. Transmission Electron Microscopy observations provided direct evidence of θ′ (Al₂Cu) precipitates. The 3 wt.% WC composite reached peak hardness after 5 h (78 HRF), a 15% increase over the T6-treated unreinforced alloy, and exhibited a 40% higher yield strength (330 MPa). These improvements were attributed to the combined effects of Orowan strengthening and age-hardening precipitates (θ′). The results demonstrate that integrating powder metallurgy, sub-micron WC reinforcement, and T6 treatment is an effective route to enhance strength in Al–Cu–Mg alloys without delaying aging kinetics.