State Route 48 (SR 48) is a north–south highway in Ohio that runs from SR 132 near Goshen to SR 66 near Houston, passing through Dayton.

In the early 20th century, SR 48 was assigned to completely unrelated routes within the state. From 1923 to 1927, it was the designation given to Barnesville–Hendrysburg, Barnesville–Woodsfield, and Woodsfield–Sistersville roads in eastern Ohio, now designated SR 800. Present-day SR 48 was previously signed as SR 50, and before that as Dayton–Covington and Dayton–Lebanon roads. (See 1923 Ohio state highway renumbering and 1927 Ohio state highway renumbering).

In I Love Lucy episode #111, "First Stop", the Ricardos and the Mertzes travel this route, although they were headed to Cincinnati.[citation needed]