Because social anxiety and depression commonly co-occur, it can be challenging to disentangle the emotional and motivational features of these conditions in everyday life contexts. In this daily diary study, we sought to understand the interplay between daily social anxiety and depression symptoms and emotion and motivation, determining whether daily symptoms are independently linked with positive affect, negative affect, and social motivation (desire to approach or to withdraw from others). Community-dwelling adults (N = 269) with a wide range of social anxiety and depression symptoms completed daily assessments for 14 consecutive days (a total of 2,986 daily surveys). Within-person analyses found that increases in social anxiety and depression symptoms were uniquely associated with elevated negative affect; only increases in depression symptoms were associated with diminished positive affect. Increases in social anxiety symptoms were associated with an elevated desire to approach others but not a desire to withdraw from others. By contrast, increases in depression symptoms were associated with a diminished desire to approach others and an elevated desire to withdraw from others. Desire for social connection may distinguish social anxiety from depression. Examining patterns of daily social motivation may enhance clinicians' ability to differentiate the difficulties that arise from social anxiety from those that arise from depression.