The 2018 Cary Challenger was a professional tennis tournament played on hard courts. It was the 4th edition of the tournament which was part of the 2018 ATP Challenger Tour. It took place in Cary, North Carolina, United States between 10 and 16 September 2018.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Canada | Peter Polansky | 119 | 1 | |
 Sweden | 132 | 2 | ||
| Marcelo Arévalo | 146 | 3 | ||
| Reilly Opelka | 173 | 4 | ||
| Bjorn Fratangelo | 175 | 5 | ||
| Kevin King | 180 | 6 | ||
 Australia | Alexei Popyrin | 195 | 7 | |
| Australia | Maverick Banes | 216 | 8 |
The following players received wildcards into the singles main draw:
William Blumberg Alexis Galarneau Sebastian Korda Nick StachowiakThe following players received entry from the qualifying draw:
Joris De Loore James Duckworth Evan Song J. J. WolfSee main article: 2018 Cary Challenger – Singles.
James Duckworth def. Reilly Opelka 7–6(7–4), 6–3.See main article: 2018 Cary Challenger – Doubles.
Evan King / Hunter Reese def. 
Fabrice Martin / Hugo Nys 6–4, 7–6(8–6).