The 2013 San Marino CEPU Open was a professional tennis tournament plays on clay courts. It was the 26th edition of the tournament which is part of the Tretorn SERIE+ of the 2013 ATP Challenger Tour. It takes place in City of San Marino, San Marino between 5 and 11 August 2013.
| Country | Player | Rank1 | Seed | |
|---|---|---|---|---|
 Spain | Daniel Gimeno Traver | 62 | 1 | |
 Romania | Adrian Ungur | 92 | 2 | |
 France | Guillaume Rufin | 96 | 3 | |
 Czech Republic | Jiří Veselý | 98 | 4 | |
| Jan-Lennard Struff | 103 | 5 | ||
 Italy | Filippo Volandri | 105 | 6 | |
| Jesse Huta Galung | 110 | 7 | ||
| Blaž Kavčič | 120 | 8 |
The following players received wildcards into the singles main draw:
Marco Cecchinato Alessandro Giannessi Gianluigi Quinzi Stefano TravagliaThe following players received entry from the qualifying draw:
See main article: 2013 San Marino CEPU Open – Singles.
Marco Cecchinato def. Filippo Volandri 6–3, 6–4See main article: 2013 San Marino CEPU Open – Doubles.
Nicholas Monroe / Simon Stadler def. Daniele Bracciali / Florin Mergea 6–2, 6–4