Phosphogypsum may be recycled for utilization as part of lightweight building materials, which are widely studied due to their excellent thermal resistance and acoustic performance. Thus, in this study, phosphogypsum was explored as a raw material to produce fiber-reinforced lightweight foamed phosphogypsum-based material (LFPM) where hydrogen peroxide (H₂O₂) and sodium lauryl sulfate (SLS) were employed as a foaming agent and surfactant, respectively. The effect of H₂O₂ (0%–2.5%) and SLS (0%–3.0%) on the mechanical strength, water resistance, thermal conductivity, and sound absorption of the polyvinyl alcohol fiber (PVA) fiber-reinforced LFPM was assessed. Additionally, the macrostructure and microstructure of the PVA fiber-reinforced LFPM were investigated. The H₂O₂ had a similar effect as SLS, which reduced the mechanical strength and water resistance but contributed to lowering the thermal conductivity and increasing the sound absorption of the PVA fiber-reinforced LFPM. SLS can stabilize foams by reducing surface tension and generating more uniform and finer pores, which can further improve the thermal conductivity and sound absorption. The optimized LFPM with a bulk density of 794 kg m⁻³, thermal conductivity of 0.201 W m⁻¹ K⁻¹, and average sound absorption coefficient of 0.492 can be produced with 1.5% H₂O₂ and 0.6% SLS, suitable for non-load-bearing applications.