Methods and apparatus for fusing multiple databases into a single database are disclosed. A disclosed method determines a ranking of a plurality of matching variables associated with first and second datasets and generates a hierarchical matching grid including a plurality of levels based on the ranking of the plurality of matching variables. The example method identifies first and second sets of match candidates from the first and second datasets based on successive levels of the hierarchical matching grid and fuses records in the first and second sets of match candidates based on probabilities associated with the records.