Line intensities, self- and air-broadened linewidths, pressure-induced shifts, and collisional narrowing coefficients were measured from 2⩽J′⩽32 in the P branch of the O 2 A-band (12975–13110cm −1 ) utilizing Galatry line profiles. Spectra were recorded using the frequency-stabilized cavity ring-down spectrometer located at NIST, Gaithersburg, MD with a spectral resolution <0.0001cm −1 and noise-equivalent absorption coefficient of 6×10 −8 m −1 Hz −1/2 . Line intensities, obtained from calibrated gas samples for 2⩽J′⩽32, are ∼1% lower than the values in current spectroscopic databases. At higher J (18⩽J′⩽32), the measured air- and self- broadened half widths are up to 20% lower than the extrapolated values given in HITRAN 2004, while corresponding half-widths for 2⩽J′⩽15 are in better agreement. Available self-broadened half widths are fitted to empirical expressions with an rms of 0.8%. We discuss the implications of our results for accurate remote sensing of surface pressure and photon path length distributions.