X.O Suki is a steamboat restaurant located inside Sun Plaza Medan. Based on the observation of the writer, this restaurant has problems in service quality where this was also commented by customer who had visited this restaurant through interview with the writer.Service quality is the evaluation of customers to determine how well the services provided in the restaurant. The hypothesis for this research is there is a significant influence of services quality toward customer satisfaction in X.O Suki Sun Plaza Medan. This study aims to analyze and find out the influence of services quality toward customer satisfaction in X.O Suki Sun Plaza Medan. This study uses quantitative research methods (descriptive and correlation analysis) and collecting questionnaire from 80 respondents by using convenience sampling techniques.The results of the analysis data show questionnaire items for validity and reliability tested with 30 samples are valid and reliable. Correlation test has a correlation of 0.853, correlation determination = 73.6%, simple linear regression (Y = 6.565 + 0.853 X),T-test calculation resulted T Count is 14.730 and T Table is 1.66, which means that Ho is rejected and Ha is accepted because T Count is greater than T Table. The conclusion for this research is there is a significant influence of services quality toward customer satisfaction in X.O Suki Sun Plaza Medan. The recommendation of this research are X.O Suki need to pay attention for the service quality, Employee encouraged to provide good performance, and for other researchers are need to have complete data when conduct a research.