The wetland ecosystem represents a crucial ecological resource, supporting diverse flora and fauna while providing essential services to the local communities. However, rapid human settlement within its environment has raised concerns to play it important functions. The study assessed the effect of human settlement on wetland ecosystem sustainability at Lake Kenyatta Wetland in Lamu West Sub-County. This study adopted descriptive research design. The target population of the study was 2750 persons comprising of households from Lamu West Sub-County, three chiefs, and three sub-chiefs surrounding Lake Kenyatta Wetland Ecosystem and four environmental officers from Lamu County. The sample size of the study was 185 respondents; it was determined using Krejcie & Morgan (1970) formulae. Primary data was collected using questionnaires and interview guides. Quantitative data was analyzed using descriptive statistics in the form of means, and percentages and presented in tables and figures. The study findings on effect of human settlement showed that majority of the respondents 93.8% agreed that human settlement practices have hindered the long-term sustainability and resilience of Lake Kenyatta wetland, and thus human activities can introduce invasive plant and animal species into wetlands. In conclusion, human settlement has affected the ecological health and balance of the wetland ecosystem. The impact of human activities has led to degradation, habitat destruction, and hindered long-term sustainability of the lake. The study recommended that stakeholders engage in comprehensive community consultations and awareness programs. Collaborative efforts involving local authorities, environmental agencies, and community leaders are crucial for implementing sustainable policies that balance economic opportunities with environmental preservation