This study aimed to describe the relationships between leisure boredom, leisure satisfaction, and smartphone addictions among university students. The study sample consisted of 258 participants, 143 males and 115 females, studying at Istanbul University-Cerrahpaşa Faculty of Sports Sciences. The participants were selected using the purposeful sampling method. Data collection tools involved a personal information form, the "Leisure Boredom Scale (LBS)", the "Leisure Satisfaction Scale (LSS)" and "Smartphone Addiction Scale-Short Version (SAS-SV)". Independent t-Test results revealed a significant difference in SAS-SV by gender. The MANOVA results indicated a significant difference between the "Satisfaction" sub-dimension of LBS and the "Educational," "Social," "Physical," and "Relaxation" sub-dimensions of LSS by gender. A significant difference was found between LBS's "Satisfaction" sub-dimension and all sub-dimensions of LSS by income status. According to the ANOVA results, there was no significant relationship between the SAS-SV scores by income status of the participants. Besides, there was a negative and low-level correlation between age and the "Satisfaction" sub-dimension of LBS, the "Physical" and "Relaxation" sub-dimensions of LSS and SAS-SV. There was a negative and low correlation between "Boredom" of LBS and "Psychological," "Social," and "Relaxation" sub-dimensions of LSS, and there was a positive and low correlation between LBS and SAS-SV. Similarly, a positive and low-level relationship was determined between all sub-dimensions of LSS and SAS-SV. In this sense, it was concluded that the LBS, LSS, and SAS-SV scores differed according to the socio-demographic characteristics of the participants. As leisure boredom increased, leisure satisfaction decreased, and smartphone addiction increased. It was also found that as leisure satisfaction improved, smartphone addiction increased.