It is our great pleasure to welcome you to the 30th ACM Symposium on Parallelism in Algorithms and Architectures (SPAA 2018). SPAA has a long history of bringing together the theory and practice of parallelism, defined broadly to include any computational settings where multiple operations can be performed simultaneously or concurrently. The program reflects the diversity of parallel settings and models. This year's program includes 36 regular papers and 11 brief announcements, many of which combine both theory and practice, as well as two invited keynote lectures: The Resurgence of Software Performance Engineering by Charles E. Leiserson and Massive-Scale Streaming Analytics: Models, Parallelism, and Real-World Applications by David A. Bader. Several traditional topics are well-represented this year, including scheduling, graph algorithms, and parallel and concurrent data structures. The program also includes a significant number of papers that explore emerging memory technologies and parallelism in memory accesses. The call for papers attracted 120 submissions as regular papers plus 6 as brief announcements. From the regular submissions, 36 papers were accepted (30%). The 11 brief announcements were selected from all submissions based on the committee's perception of interest from the SPAA community, with the goal that they serve as bases for further advances in parallelism. Extended versions of brief announcements may be published in other conferences or journals.