Sea levels are always changing, for many reasons. Some changes are rapid, while others take place very slowly. The changes can be local, or extend globally. Sea levels, particularly extremes, are important for coastal flooding and coral reef development, both of which may be impacted by climate change. In this chapter, we review Red Sea sea-level changes, before looking at the various processes involved in more detail and relating them to basin development and dynamics. There is no systematic review of Red Sea levels: most scientific studies have been local and piecemeal; measurements are few and limited to widely spaced harbour facilities. This chapter is a brief overview of sea-level changes and a source of references for further studies. On increasing timescales, we review tidal, weekly, seasonal and long-term changes. Finally, we link to changes of sea level in the recent geological record.