Hadronic Higgs boson decay to order alpha(4)(s)

We present in analytic form the three-loop O(alpha(s)(2)) correction to the H --> gg partial width of the standard-model Higgs boson with intermediate mass M-H << 2M(t). Its knowledge is required because the O(alpha(s)) correction is so sizable that the theoretical prediction to this order is unlikely to be reliable. For M-H = 100 GeV, the resulting QCD correction factor reads 1 + (215/12)alpha(s)((5))(M-H)/pi + 150.419[alpha(s)((5))(M-H)/pi](2) similar to 1 + 0.66 + 0.21. The new three-loop correction increases the Higgs boson hadronic width by an amount of order 1%.