Thirty new records of fishes are reported from Johnston Atoll. Three are Hawaiian endemics, six are widespread Indo-Pacific species that reach Johnston but not Hawaii, and the remainder are widespread species that have been recorded from Hawaii and elsewhere in the Pacific. The number of fish species recorded from Johnston is raised to 301. The attenuated nature of Johnston’s fish fauna may be due to several factors, including isolation, lack of habitat area and diversity, and glacioeustatic extinctions.