This chapter presents changes in relative sea level (RSL) along tropical coastlines (30°N-30°S). Under current and future global changes, 90% of the coastlines are at risk, facing challenges of rising sea level (SL). Since the last century, scientists have attempted to understand processes governing RSL, to separate variations in absolute SL from those due to vertical land movement, and to discover their links to climate change. Recently developed space technologies provide accurate estimates of ongoing SL changes. Combined with tide gauge records, these new instruments (GPS, altimetry, InSAR) offer a new perspective for the science associated with sea level and its changes. This chapter reviews the concept of RSL, of RSL hotspots and describes different RSL measurements. Then, it identifies and maps the hotspots of RSL changes and updates, where possible, previously published estimates of RSL trends. Identification of the RSL hotspots is of paramount importance for climate change mitigation and adaptation in tropical regions.