A circuit visitor is a pastor who helps to oversee the other pastors within a circuit. The position is best understood as a peer advisor, as the LCMS has traditionally been congregational, as opposed to hierarchical, in its extra-congregational structure.
Nevertheless, there is a district president (sometimes called a bishop) over the circuit visitors who is ultimately responsible for the pastors and congregations (generally numbering 100–300) in his district. The visitors were previously called circuit counselors, but the 2013 LCMS convention adopted, and the congregations subsequently ratified, an amendment to its constitution changing their title back to what it had originally been.