Bacteriophages are ubiquitous and infect host bacteria in all environments including soil, the deep ocean, and the human body. Phages and the facultative anaerobes, like P. aeruginosa, that they infect commonly inhabit environments with harsh oxygen stresses. Facultative anaerobic growth and survival depends on their acquisition of free-oxygen and their ability to use alternative molecules like nitrogen as final electron acceptors. P. aeruginosa survives in low oxygen environments by sequestering available oxygen in biofilm matrices and through its highly branched respiratory chain containing multiple terminal oxidases and denitrification enzymes. Because phages are highly dependent on their bacterial host cells to survive, changes in host respiration may also influence phage growth. In this study, we use an in vitro system with physiologically ‘correct’ tissue oxygen tensions of 5% to accurately model physiological functions of host bacteria infecting human tissues. We determined that a reduction from 21% to 5% oxygen decreased the growth rate of P. aeruginosa by 50%, thereby limiting the culture population carrying capacity in vitro. Phage infection of P. aeruginosa begins with cell surface binding. To explore this stage, we determined the rates at which 90% of phage particles are bound to host cells under the different oxygen levels. The adsorption k constants (rate) were 3.05×10^-10 and 5.52×10^-10 under 21% and 5% oxygen, respectively. After binding and virion nucleic acid uptake, the time of virion infection itself (latent period) during which phage proteins are synthesized, nucleic acids copied, and assemble into mature virions can be characterized before “bursting” through cell lysis. We determined the latent periods to be ~26 and ~27 minutes under 21% and 5% oxygen levels. The amount of progeny virions released from infected host cells was about 184 and 179, respectively. We then sought to determine if phage population growth was decreased under low oxygen. PYO2 population growth only reached a density of 7.85×10^9 pfu/ml after 24h at 5% oxygen, whereas it grew to 4.67×10^10 pfu/ml under 21% oxygen. Taken together, low oxygen environments may have influenced P. aeruginosa to switch to other forms of respiration, such as using nitrogen instead of oxygen to fuel its metabolic processes. Although phage PYO2 adsorption rate and latent periods were similar under low oxygen, the host cell’s lower energy production appeared to reduce virion progeny production with lower burst size. This small reduction in phage growth over time lead to an 83% lower population density that may be related to decreased host growth under 5% oxygen. Phages are omnipresent with an estimated abundance of 10^31 globally with many of their environments having less than ambient oxygen levels. Although it remains to be determined in vivo, lytic phages appear capable of maintaining exponential growth in the body.