Abstract This essay is an inquiry into Heraclitus' conception of logos and its importance for sophistic thought. Following G. S. Kirk, I argue that Heraclitus used logos to designate structure or ordered composition, both in language and in the physical world. Further, I propose that early sophists like Gorgias and Protagoras shared with Heraclitus a structural conception of logos. The essay proceeds by reviewing various understandings of Heraclitus and his philosophy, making the case that Heraclitus did use logos to signify structure or “ordered composition,” and by exploring the relationship between Heraclitus, read in this way, and the sophists.