Wearing a facemask is an effective part of personal hygiene management (WHO, 2020). Not only can it offer healthy people some protection against coronavirus disease 2019 (COVID-19) infection, but it can also reduce the spread of the virus. Wearing facemasks, as a part of the various regulations and guidelines encouraged by the Chinese government and hospitality firms, has been widely accepted by the public in the post-COVID-19 era in China. But few studies have considered the effects of employees wearing facemasks on the customer service experience. Based on signaling theory, this experimental study explores the effects of hotel employees wearing facemasks on customer perceptions of service quality. The results indicate three main effects. (a) Having employees wear facemasks can improve perceptions of customer service quality. (b) Customers commonly feel that female employees wearing facemasks could provide higher service quality than male mask-wearing employees, but the improvement in customer perception with male employees wearing facemasks is greater than the situation between facemask-less and facemask-wearing females. (c) Customer perceptions of employee expertise, employee trustworthiness, and hotel trustworthiness play serial mediating roles. Recommendations to help hotel managers improve customers’ service evaluations during the COVID-19 pandemic are provided.