We present the temperature and polarization angular power spectra of the cosmic microwave background derived from the first five years of Wilkinson Microwave Anisotropy Probe data. The five-year temperature spectrum is cosmic variance limited up to multipole ℓ= 530, and individual ℓ-modes have signal-to-noise ratio S/N> 1 for ℓ< 920. The best-fitting six-parameter ΛCDM model has a reduced χ 2 for ℓ= 33–1000 of χ 2/ν= 1.06, with a probability to exceed of 9.3%. There is now significantly improved data near the third peak which leads to improved cosmological constraints. The temperature-polarization correlation is seen with high significance. After accounting for foreground emission, the low-ℓ reionization feature in the EE power spectrum is preferred by Δχ 2= 19.6 for optical depth τ= 0.089 by the EE data alone, and is now largely cosmic variance limited for ℓ= 2–6. There is no evidence for cosmic signal in the BB, TB, or EB spectra after accounting for foreground emission. We find that, when averaged over ℓ= 2–6, ℓ (ℓ+ 1) C BB ℓ/(2π)< 0.15 μK 2 (95% CL).