Small Aircraft
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 0.2
Situational Awareness
ATC Issue All Types; Aircraft Equipment Problem Less Severe; Ground Excursion Runway
Air Traffic Control Issued Advisory / Alert; Air Traffic Control Issued New Clearance
Aircraft; Airport; Human Factors
Aircraft X called up roughly 6 miles east of ZZZ with a VFR tag and stated that he was having trouble with his GPS and was [positioned southwest] and wanted to come into land; I told him to report a 2 mile left base for runway 15 and to report when he had the field in sight. He reported the field in sight at about a 3 mile final for runway 24. When he was about a mile and a half out and still lined up for RWY 24 I asked if he could circle north and land RWY 15; which was currently the advertised runway. He responded that he could and started to circle to the north. I then cleared him to land RWY 15. He then went around stating that he was too high. I gave him left closed traffic for RWY 15; and then changed it to right closed traffic for RWY 15 because there was [another aircraft] inbound from the northeast for a left base for RWY 15. I then cleared Aircraft X to land and read him the wind. He appeared to be landing long on RWY 15 and as he looked to be touching down it sounded like he hit the throttle briefly and then landed the aircraft and went off the runway to the right close to the departure end.I'm not sure what have could have been done to prevent this aircraft from exiting the runway. He appeared to be landing long but I believe had he not throttled back up he would have not exited the runway.
Tower controller reported an aircraft runway excursion after landing.