Guna Mountain Community Conservation Area is one of the places where gelada monkey have been found. In this study, the activity and ranging patterns of gelada monkey (Theropithecus gelada) were studied in Guna Mountains Community Conservation Area, South Gonder, Ethiopia, from September 2019 to February 2020. The study was aimed to investigate the activity, ranging patterns and habitat use of gelada monkey. Behavioral data on the activity budget, ranging ecology and habitat use of gelada monkey were collected using scan sampling method at 15-minute intervals. Effects of monthly variation on activity time budgets were statistically tested by MANOVA. Chi-square test was also used for testing difference on microhabitat utilization. Home range and day range length were determined based on point to point movements of the group between consecutive GPS locations recorded in the time of scan samples. Daily range length and home range size were estimated using Open Jump toolbox (MOVEAN), and statistically tested by ANOVA. Especially, MCP (95%) and MCP (100%) methods were also used to estimate home range sizes. A total of 3368 behavioral scan samples were recorded from the study group. Feeding accounted for 29.75% followed by moving 23.9% for the activity budget of gelada monkey in the study area. In a daily time pattern, socializing and resting were peak early in the morning whereas feeding was peak late in the morning and afternoon. The results of multivariate analysis reveal that month has statistically significant effect on activity time budget [Roy's Largest Root = 3.5, F = 16.8, df = (5, 24), p < 0.001, partial η2 = 0.778). The result showed that gelada monkey spent more time in montane grassland habitat (55.1%). Overall habitat utilization of the gelada monkey in the different micro-habitats is statistically different (χ2=7.631, df=2, p=0.022). The average daily range length of gelada monkey was 1712.3± SD 1050.6 m. But, differences in the daily travel distance across months were significant (F = 1.44, df = 5, P = 0.046). The estimated home range size using 95% MCP and 100% MCP were 0.42 km2 and 1.1 km2, respectively. The results showed that the gelada monkey spent less time on feeding compared to previous studies at the Simien Mountains, Debre-Libanos area, Guassa Community Conservation Area, due to higher habitat disturbance in the area. Therefore, conservation resource should be undertaken to save the gelada monkey in this highly disturbed environment.