Izmir, with its long coastline, is one of Turkey's leading tourism and trade cities. The coastal flood is an important problem in İzmir Bay. The literature review shows that there is no study that covers all the elements of the problem such as wind and wave climate, fluctuations in the sea level and coastal flood calculations in İzmir Bay. In this study, the ERA5 wind dataset developed by the European Center for Medium Range Weather Forecasts was used to determine extreme wind speeds. The data were verified using in-situ wind measurements data. Then, the fluctuations in sea water level caused by astronomic and atmospheric effects such as tides, wind and wave set-up and barometric effects were examined by the analysis of sea water level measurement data of the Izmir Metropolitan Municipality in Bostanlı and Pasaport and the tide gauge station data of the General Directorate of Mapping in Mentes. The long-term trend of sea level was examined using Theil-Sen and the line of best-fit methods. Then, the reliability of the trends was demonstrated by performing the Mann-Kendal test. Calculated extreme wind speeds and sea level fluctuations were taken into account to estimate the waves in front of coastal protection structures using a wave model called SWAN. Then, in order to predict the coastal flood amounts, the wave overtopping was calculated by the artificial neural network method. It is concluded that the most sensitive places in İzmir Bay in terms of coastal floods are the areas protected by vertical walls.