<p>How does scene viewing develop? Previous evidence is limited and suggests that viewing behaviour may be adult-like from about eight years old. Here we present data from <i>n</i> = 6,720 participants from 5 to 72 years old, freely viewing 40 natural scenes. We found that the development of scene viewing is surprisingly protracted. Semantic salience for social features continuously changes until adolescence, and text salience increases over the first two decades of life. Basic oculomotor biases towards the image centre and along the horizontal meridian develop until adolescence, matching developmental changes in visual sensitivity and cortex. Finally, while the tendency for visual exploration continuously increases, fixation patterns become less idiosyncratic and more canonical throughout adolescence. These findings show that fundamental aspects of adult gaze take up to two decades of continuous development and push individuals towards more canonical viewing patterns. We suggest that development is key to understanding the general mechanisms of active vision.</p>