It’s been said, “The farther backwards you look, the farther forward you are likely to see” (Sir Winston Churchill, 1874–1965). This is especially true in science where knowledge is cumulative and contemporary challenges are built on the successes of the past. Microbial oceanography is a relatively new discipline that endeavors to establish a comprehensive understanding of sea microbes, from genomes to biomes, thereby coupling biosystems to ecosystems. Microbial oceanography has its historic roots in the more established fields of microbiology, oceanography, and marine biology. Many current practitioners, however, are unaware of some of the key benchmarks and the contributors who helped to establish their discipline. Our introduction presents a few selected waypoints in microbial oceanography.