The 2013 Nielsen Pro Tennis Championship was a professional tennis tournament played on hard courts. It was the 22nd edition of the tournament which was part of the 2013 ATP Challenger Tour. It took place in Winnetka, Illinois, between 1 and 7 July 2013.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Russian Federation | Alex Bogomolov Jr. | 81 | 1 | |
| Steve Johnson | 98 | 2 | ||
| Jack Sock | 102 | 3 | ||
| Tim Smyczek | 120 | 4 | ||
 India | Somdev Devvarman | 136 | 5 | |
| Mischa Zverev | 145 | 6 | ||
| Donald Young | 154 | 7 | ||
| Bradley Klahn | 178 | 8 |
The following players received wildcards into the singles main draw:
Jarmere Jenkins Evan King Dennis Nevolo Jack SockThe following players received entry as an alternate into the singles main draw:
The following players received entry from the qualifying draw:
See main article: 2013 Nielsen Pro Tennis Championship – singles.
Jack Sock def. Bradley Klahn 6–4, 6–2See main article: 2013 Nielsen Pro Tennis Championship – doubles.
Yuki Bhambri / 
Michael Venus def. Somdev Devvarman / Jack Sock 2–6, 6–2, [10–8]