Emotions and motivation are important for learning and achievement in mathematics. In this paper, we present an overview of research on students' emotions and motivation in mathematics. First, we briefly review how early research has developed into the current state-of-the-art and outline the following key characteristics of emotions and motivation: objects, valence, temporal stability (vs. variability), and situational specificity (vs. generality). Second, we summarize major theories in the field (the control-value theory of achievement emotions, expectancy-value theory of achievement-related motivation, self-determination theory of human motivation, and social-cognitive theory of self-efficacy). Third, we present an overview of instructional characteristics that have been shown to foster emotions and motivation. Fourth, we provide an overview of the contributions to the special issue on "Emotions and Motivation in Mathematics Education and Educational Psychology." Finally, we suggest directions for future research in the field with respect to advancing theory, improving measurement, and considering diversity and inclusion.