Lucas is located at {{coord|40|42|14|N|82|25|12|W|type:city}} (40.703773, -82.420024).<ref name="GR1">{{cite web|url=https://www.census.gov/geographies/reference-files/time-series/geo/gazetteer-files.html|publisher=[[United States Census Bureau]]|accessdate=2011-04-23|date=2011-02-12|title=US Gazetteer files: 2010, 2000, and 1990}}</ref> It lies southeast of Mansfield, a few miles from [[Interstate 71]] on [[Ohio State Route 39|State Route 39]]. Lucas is surrounded by the Rocky Fork and [[Black Fork Mohican River|Black Fork]] rivers, and the [[Charles Mill Lake]] to the east, and the Pleasant Hill Lake to the south. Lucas has many hills and forests and is part of the Mohican Valley area, along with [[Loudonville, Ohio|Loudonville]], [[Perrysville, Ohio|Perrysville]], [[Butler, Ohio|Butler]] and [[Bellville, Ohio|Bellville]]. According to the [[United States Census Bureau]], the village has a total area of {{convert|0.69|sqmi|sqkm|2}}, all land.<ref name="Gazetteer files">{{cite web|title=US Gazetteer files 2010 |url=https://www.census.gov/geo/www/gazetteer/files/Gaz_places_national.txt |publisher=[[United States Census Bureau]] |accessdate=2013-01-06 |url-status=dead |archiveurl=https://web.archive.org/web/20120125061959/http://www.census.gov/geo/www/gazetteer/files/Gaz_places_national.txt |archivedate=2012-01-25 }}</ref>
