Haemophilus influenzae (Hi) is a leading cause of mucosal infections and exacerbations of chronic lung diseases such as asthma and COPD. Hi strains are increasingly acquiring antibiotic resistance, complicating treatment. Metabolic targets could provide new options for the development of Hi treatments, and enzymes for the uptake of exogenous pyrimidines such as uracil and uridine could be a potential Achilles heel for Hi as it lacks key enzymes for pyrimidine biosynthesis. Here, we have investigated the role of uracil and uridine uptake via the uraA and nupC transporters, and the subsequent conversion of uracil to UMP by udp and udk in Hi physiology. Growth of mutant strains in these genes revealed 16-37%(ΔnupC, ΔuraA, Δudp) reduced growth rates and ~30% lower final OD600 in uracil-supplemented-media while Δudk showed no significant change. Orotate addition partially restored growth in ΔuraA and Δudp strains, confirming their key roles in uracil transport and its use as a pyrimidine source. Use of uridine as the sole carbon and pyrimidine source reduced the final OD600 of the ΔnupC-strain 2.5-fold, indicating its involvement in uridine uptake. Virulence-related properties were assessed through biofilm formation, which was reduced by ~40%(Δudp) to >60%(ΔuraA, ΔnupC). Furthermore, ΔuraA and ΔnupC strains were more sensitive to oxidative stress, implying a potential reduction in infection fitness. The most striking phenotypes were obtained for infection of human 16HBE14 bronchial cells, where after 24h co-culture, 20-30 fold reductions in total adherent cells were observed, while, strikingly, intracellular bacteria decreased ~300-fold(Δudp, Δudk) to ~600-fold (ΔnupC, ΔuraA) compared to WT, linking pyrimidine salvage to Hi intracellular survival. Further work is needed to elucidate the molecular processes underpinning the impact of pyrimidine acquisition loss on Hi virulence. However, our results so far indicate it is an essential process and could provide a target for infection control.