A patent office is a governmental or intergovernmental organization which controls the issue of patents.
In other words, "patent offices are government bodies that may grant a patent or reject the patent application based on whether the application fulfils the requirements for patentability.
"[1] For a list of patent offices and their websites, see the World Intellectual Property Organization (WIPO) maintained list, here.
The entries shown in italics are regional or international patent offices.