Tennessee Constitution
Article III - Executive Department.
Section 4

The governor shall be elected to hold office for four years and until a successor is elected and qualified. A person may be eligible to succeed in office for additional four year terms, provided that no person presently serving or elected hereafter shall be eligible for election to more than two terms consecutively, including an election to a partial term.

One succeeding to the office vacated during the first eighteen calendar months of the term shall hold office until a successor is elected for the remainder of the term at the next election of members of the General Assembly and qualified pursuant to this Constitution. One succeeding to the office vacated after the first eighteen calendar months of the term shall continue to hold office for the remainder of the full term.