The negative impact of agricultural land on biodiversity is widely recognized. However, there remains a knowledge gap regarding the role of different crop types in maintaining biodiversity within the agricultural landscape. By extracting biodiversity data from global datasets and classifying different crop types, we quantified the contribution of different crop types to biodiversity. Our results indicate that biodiversity levels vary widely among crop types. We found a general loss of biodiversity when natural vegetation is converted to agricultural land, and highest losses in fiber crops, cereals and oil crops, and least in other crops (such as coffee or cocoa) and in mixed crops. In general, perennial crops retain more biodiversity than annual crops. Losses of biodiversity can be mitigated through mixed cropping of multiple crop types, especially by combining annual and perennial crops. The negative impact of converting natural vegetation to agriculture is greater in tropical than in nontropical areas, and hence, the import of commodities from these biodiversity‐rich regions may be particularly detrimental. Given the ongoing increase in biodiversity losses from global intensification and expansion of agricultural land, maintaining or restoring natural vegetation, rating the crop‐type‐specific biodiversity, diversifying crops, and preferring perennial over annual crops, particularly in the tropics, need to be better considered and implemented in global agri‐environmental schemes.