A Citizen Science initiative by the Westerdijk Fungal Biodiversity Institute and the Utrecht University Museum gave rise to a project where fungal and yeast isolates were obtained and identified from Dutch soil samples. During the current study, 386 yeast strains were isolated from 157 different locations in the Netherlands. These strains were identified using sequence data of the large-subunit rRNA gene (D1/D2 region) and the internal transcribed spacer 1 and 2 regions. A total of 53 different yeast species were found as well as 15 potentially novel species. Six novel ascomycetous species are described during this study that include Hanseniaspora mollemarum sp. nov., Ogataea degrootiae sp. nov., Pichia gijzeniarum sp. nov., Saccharomycopsis oosterbeekiorum sp. nov., Trichomonascus vanleenenius sp. nov. and Zygoascus flipseniorum sp. nov. This study made it possible to incorporate numerous yeast isolates into the CBS collection without any restrictions, which make these isolates readily available for use by others. Many of the isolates represented species of which only a few isolates or even only a single ex-type strain were available. Therefore, it is a clear indication that such biodiversity-orientated Citizen Science projects can enrich the pool of available yeasts for future research projects.