Homogeneous catalysis is catalysis in which the catalyst is present in the same phase as the reactants, for example a dissolved catalyst in a solution of reactants. Because catalyst and reactants are uniformly mixed, the catalyst can act throughout the reaction mixture. It contrasts with heterogeneous catalysis, where the catalyst is in a different phase.

均相催化是催化剂与反应物处于同一相的催化,例如溶解在反应物溶液中的催化剂。由于催化剂与反应物均匀混合,催化剂能在整个反应混合物中起作用。它与催化剂处于不同相的多相催化相对。