Global Englishes language teaching (GELT) promotes, among other things, positive attitudes and maximized understanding to communicate with speakers with a variety of accents. However, research on GELT-informed listening training is rare, and none has addressed both attitudes and understanding of diverse accents. We therefore implemented an intervention to foster listening skills and attitudes needed for Global Englishes communication, drawing on mediated contact and high-variability training. An intermediate-level English class (N = 27) in a Swedish upper secondary school engaged in six 20- to 30-minute activities over 3 weeks, intended to promote positive images of Global Englishes speakers from diverse backgrounds and help learners expand their perceptual repertoire. The activities significantly improved listener intelligibility (actual understanding), listener comprehensibility (ease of understanding), and language-focused accent attitudes toward two speakers whose accents were not represented in the training, compared to a control group (N = 24). However, status-related accent attitudes connected to entrenched language ideologies were unchanged. Post-intervention focus group data (N = 4) provided a more detailed understanding of the effects and limitations of our intervention. Our findings suggest that listening training for a wide range of Global Englishes accent varieties is possible with a limited number of accent samples and can be easily integrated into the English classroom.