We have recorded rovibronic bands of C₆H₅O and C₆D₅O in their A²B₂ <- X ²B₂ transitions in the range 1.15-1.32 micrometer with the cavity ringdown technique. By comparison of simulated rovibronic contours and vibrational wavenumbers based on quantum-chemical calculations, we derived vibrational wavenumbers of the A ²B₂ state, namely v₁₂ = 948, v₁₃ = 792, v₁₄ = 417, v₁₅ = 928, v₁₆ = 867, v₁₇ = 723, v₁₈ = 680, and v₁₉ = 499 cm^-1 for C₆H₅O, and v₁₂ = 772, v₁₃ = 626, v₁₄ = 365, v₁₅ = 811, v₁₇ = 599, v₁₈ = 532, and v₁₉ = 401 cm^-1 for C₆D₅O, in good agreement with predictions from quantum-chemical calculations at the UB3LYP/aug-cc-PVDZ level.. Transitions involving vibrationally excited levels of v₂₀ were also observed. A weak origin at 7681 cm^-1 for the A <- X transition of C₆H₅O (7661 cm^-1 for C₆D₅O) with c-type contour was also observed.