Rap(p)aport, Rap(p)oport or Rapa Porto (Hebrew: רפפורט) is a family name from an Italian (Jewish) Kohenitic pedigree. It takes its origins in the Rapa family of Porto located in Province of Mantua, Italy.
Recorded evidence concerning the names of Rapa or Rappe ha-Kohen(-Tzedeq (Rapa Katz)) date from about 1450, when Meshullam Kusi (abbreviated from "Jekuthiel") Rapa ha-Kohen Tzedeq, the earliest known member of the family, lived on the Rhine, probably in Mainz. Several decades later the family disappeared from Germany, probably on account of the Jews' expulsion from Mainz on October 29, 1462. In 1467, in Mestre, near Venice, the wealthy Chayyim Rappe is found as alms collector for the poor of the Holy Land. In Venice, the physician R. Moses Rap was exempted in 1475 from wearing the Jew's badge.
In the middle of the 16th century there appeared in Italy a Kohenitic family of the name of Porto. On March 18, 1540, R. Isaac Porto ha-Kohen obtained from the Duke of Mantua permission to build an Ashkenazic synagogue. The name of the family was not derived from the Portuguese city of Porto, nor from the Bavarian city of Fürth as some authors have suggested, but instead from Porto, near Mantua, where the above-named Isaac Porto ha-Kohen lived. An alliance between the Rabe and Porto families explains the combination of the two family names in Rapoport; in 1565, officiating in the above-mentioned synagogue of Mantua, there is found a Rabbi Solomon ben Menahem ha-Kohen Rapa of Venice, while a Rabbi Abraham Porto ha-Kohen (1541–76) was parnas of the community.