To whom is a patent granted when filed by someone other than the inventor?

When a patent is granted on an application filed by someone other than the inventor, it is issued to the real party in interest. This is stipulated in both 35 U.S.C. 118 and 37 CFR 1.46(e):

35 U.S.C. 118 states: If the Director grants a patent on an application filed under this section by a person other than the inventor, the patent shall be granted to the real party in interest and upon such notice to the inventor as the Director considers to be sufficient.

37 CFR 1.46(e) further clarifies: If a patent is granted on an application filed under this section by a person other than the inventor, the patent shall be granted to the real party in interest. Otherwise, the patent may be issued to the assignee or jointly to the inventor and the assignee as provided in § 3.81.