The main aim of the current study was to investigate the role of teacher–child relationship quality in kindergarten on children’s motivation (interest in reading and task persistence) and reading skills in Grade 1. A total of 231 children (age at baseline 6.8 years; 50.6% girls) completed reading-related tasks and answered questions about their interest in reading. Eighteen kindergarten teachers completed questionnaires about the teacher–child relationship for each child in kindergarten. School psychologists reported on children’s task persistence during tests. A cross-lagged path model analysis revealed that teacher–child conflict in kindergarten predicted lower task persistence and interest in reading at the beginning of Grade 1. In addition, we found two indirect effects of teacher–child conflict in kindergarten on reading skills at the end of Grade 1 via task persistence and interest in reading at the beginning of Grade 1. The current study emphasizes the importance of teacher–child relationship quality in kindergarten and its longitudinal effects on the development of children’s motivation and reading skills in Grade 1.