The 45th ACM Symposium on Theory of Computing (STOC 2013), sponsored by the ACM Special Interest Group on Algorithms and Computation Theory (SIGACT), will be held in Palo Alto, CA from Saturday, June 1 to Tuesday, June 4, 2013. Saturday will be a day of tutorials and workshops, with the main conference program Sunday-Tuesday at the at the Palo Alto Sheraton hotel. The program will include original research on the theory of computation. Topics of interest include but are not limited to: algorithms and data structures, computational complexity, algorithmic coding theory, algorithmic graph theory and combinatorics, approximation algorithms, computational geometry, computational learning theory, cryptography, economics and computation, optimization, parallel and distributed algorithms, quantum computing, randomness in computing, and theoretical aspects of other CS-research areas, e.g., computational science, databases, information retrieval, networking, privacy, and security.