Background: Recent research emphasizes the role of the classroom context in promoting self-regulation development. However, the results are equivocal. Additionally, research tends to focus on studying the two extremes of classroom contexts (e.g., teacher fully involved vs. teacher absent during a task), which does not represent the everyday reality of the classroom. Aims: To explore the extent to which children's self-regulation differs across activities with different instructional characteristics, while adopting a fine-grained approach, which explores the middle ground between the two extremes of classroom contexts. Sample: The participants were 36 children aged 6-8 (50% female). Methods: The children participated in a variety of activities in classroom contexts that differed in terms of: (1) level of teacher involvement, (2) whether activities were teacher-initiated and -led or child-initiated and -led, and (3) social context, that is, individual, pair, or group tasks. More than 15,000 micro-episodes of self-regulatory behaviours were coded, based on the C.Ind.Le coding framework. Results and Conclusions: The classroom context had an effect on children's self-regulation rates. The children showed significantly more self-regulation when the teacher was absent, compared to involved in the activity, and more self-regulation when the teacher was involved compared to just present. More self-regulation was evident when the activity was either completely teacher-initiated and led or child-initiated and led, compared to teacher-initiated but child-led. Finally, the rate of self-regulation was significantly higher in pair and individual activities, compared to larger-group activities. These findings could support policy and practice to promote contexts that encourage self-regulatory development.