An austenitic stainless steel weld joint comprising a base material and a weld metal, wherein a chemical composition of the base material consists of, in mass%: C: 0.030% or less; Si: 0.10 to 1.00%; Mn: 0.20 to 2.00%; P: 0.040% or less; S: 0.010% or less; Cr: 16.0 to 25.0%; Ni: 10.0 to 30.0%; Mo: 0.10 to 5.00%; Nb: 0.20 to 1.00%; N: 0.050 to 0.300%; sol.Al: 0.001 to 0.100%; B: 0.0010 to 0.0080%; Cu: 0 to 5.00%; W: 0 to 5.0%; Co: 0 to 1.0%; V: 0 to 1.00%; Ta: 0 to 0.20%; Hf: 0 to 0.20%; Ca: 0 to 0.010%; Mg: 0 to 0.010%; and rare earth metals: 0 to 0.100%, with the balance being Fe and impurities, and satisfying Formula, and in the weld metal, at a width-center position and at a thickness-center position, a chemical composition of the weld metal consists of, in mass%: C: 0.050% or less; Si: 0.01 to 1.00%; Mn: 0.01 to 3.00%; P: 0.030% or less; S: 0.015% or less; Cr: 15.0 to 25.0%; Ni: 20.0 to 70.0%; Mo: 1.30 to 10.00%; Nb: 0.05 to 3.00%; N: 0.150% or less; B: 0.0050% or less; sol.Al: 0 to 1.000%; Cu: 0 to 2.50%; W: 0 to 1.0%; Co: 0 to 15.0%; V: 0 to 0.10%; Ti: 0 to 0.50%; Ta: 0 to 0.20%; Ca: 0 to 0.010%; Mg: 0 to 0.010%; and rare earth metals: 0 to 0.100%, with the balance being Fe and impurities: B + 0.004 − 0.9 C + 0.017 Mo 2 ≥ 0 where symbols of elements in Formula are to be substituted by contents of corresponding elements, in mass %. a chemical composition of the base material consists of, in mass%: C: 0.030% or less; Si: 0.10 to 1.00%; Mn: 0.20 to 2.00%; P: 0.040% or less; S: 0.010% or less; Cr: 16.0 to 25.0%; Ni: 10.0 to 30.0%; Mo: 0.10 to 5.00%; Nb: 0.20 to 1.00%; N: 0.050 to 0.300%; sol.Al: 0.001 to 0.100%; B: 0.0010 to 0.0080%; Cu: 0 to 5.00%; W: 0 to 5.0%; Co: 0 to 1.0%; V: 0 to 1.00%; Ta: 0 to 0.20%; Hf: 0 to 0.20%; Ca: 0 to 0.010%; Mg: 0 to 0.010%; and rare earth metals: 0 to 0.100%, with the balance being Fe and impurities, and satisfying Formula, and C: 0.030% or less; Si: 0.10 to 1.00%; Mn: 0.20 to 2.00%; P: 0.040% or less; S: 0.010% or less; Cr: 16.0 to 25.0%; Ni: 10.0 to 30.0%; Mo: 0.10 to 5.00%; Nb: 0.20 to 1.00%; N: 0.050 to 0.300%; sol.Al: 0.001 to 0.100%; B: 0.0010 to 0.0080%; Cu: 0 to 5.00%; W: 0 to 5.0%; Co: 0 to 1.0%; V: 0 to 1.00%; Ta: 0 to 0.20%; Hf: 0 to 0.20%; Ca: 0 to 0.010%; Mg: 0 to 0.010%; and rare earth metals: 0 to 0.100%, with the balance being Fe and impurities, and satisfying Formula, and in the weld metal, at a width-center position and at a thickness-center position, a chemical composition of the weld metal consists of, in mass%: C: 0.050% or less; Si: 0.01 to 1.00%; Mn: 0.01 to 3.00%; P: 0.030% or less; S: 0.015% or less; Cr: 15.0 to 25.0%; Ni: 20.0 to 70.0%; Mo: 1.30 to 10.00%; Nb: 0.05 to 3.00%; N: 0.150% or less; B: 0.0050% or less; sol.Al: 0 to 1.000%; Cu: 0 to 2.50%; W: 0 to 1.0%; Co: 0 to 15.0%; V: 0 to 0.10%; Ti: 0 to 0.50%; Ta: 0 to 0.20%; Ca: 0 to 0.010%; Mg: 0 to 0.010%; and rare earth metals: 0 to 0.100%, C: 0.050% or less; Si: 0.01 to 1.00%; Mn: 0.01 to 3.00%; P: 0.030% or less; S: 0.015% or less; Cr: 15.0 to 25.0%; Ni: 20.0 to 70.0%; Mo: 1.30 to 10.00%; Nb: 0.05 to 3.00%; N: 0.150% or less; B: 0.0050% or less; sol.Al: 0 to 1.000%; Cu: 0 to 2.50%; W: 0 to 1.0%; Co: 0 to 15.0%; V: 0 to 0.10%; Ti: 0 to 0.50%; Ta: 0 to 0.20%; Ca: 0 to 0.010%; Mg: 0 to 0.010%; and rare earth metals: 0 to 0.100%, with the balance being Fe and impurities: B + 0.004 − 0.9 C + 0.017 Mo 2 ≥ 0 where symbols of elements in Formula are to be substituted by contents of corresponding elements, in mass %.