Limiting global temperature rise to 1.5°C requires transformations in every aspect of our societies and economies. In contrast to 2°C pathways, the 1.5°C target requires even deeper and faster cuts in emissions. While this will bring enormous collective benefits, mitigation action also risks significant disruptions and losses to some groups. In this Perspective, we set out the justice implications of 1.5°C-consistent modelled pathways, focusing on fossil fuel extraction, critical resources, economic impacts and human needs. This leads to the identification of three cross-cutting characteristics of just transitions to 1.5°C-consistent pathways: the inherently politicised nature of transitions; the need to integrate multiple perspectives; and the challenges they present to values and assumptions. We propose a research agenda which recommends ways in which research must be interdisciplinary, integrative of diverse actors and perspectives, and able to robustly test and explore radical ideas if researchers are to rise to the challenge of delivering just transitions to 1.5°C.