Context <p>Landscape connectivity assessments have almost exclusively relied on two-dimensional (2D) representations of the landscape, where any vertical heterogeneity–such as tree height–is collapsed into a 2D pixel representing only the land cover type. In reality though, species make movement and behavior decisions based not only on land cover but also the three-dimensional (3D) height and structure of objects on the surface of the earth, including trees, shrubs, and buildings. With the rise in availability of 3D datasets, there are new opportunities to incorporate the vertical dimension into landscape assessments, but landscape connectivity has received less attention, likely because there is not yet a comprehensive framework for conceptualizing the many ways in which connectivity can be represented and measured in 3D.</p> Objectives <p>We present a framework for conceptualizing and measuring 3D connectivity across three paradigms commonly employed in landscape ecology: the patch-mosaic, graph-based, and gradient surface models.</p> Methods <p>Using these three paradigms, we outline nine different ways in which 3D data can be manipulated and integrated into connectivity measurements.</p> Results <p>We discuss how existing metrics can be adapted and where new metrics may be needed to fully realize the potential of 3D data in landscape and movement ecology.</p> Conclusions <p>As 3D connectivity research emerges, we urge researchers to be explicit about the way in which 3D data models are being incorporated into metrics and how those decisions might impact findings.</p>