Adults with an intellectual disability have significantly lower levels of fitness compared with the general population. This study examined the effects of a 13-week theoretically guided, community-based, multicomponent resistance training intervention, resistance training for empowerment, on muscular strength and independent functional performance in 24 adults with an intellectual disability, aged 18–44 years. Twelve participants were randomly allocated to an experimental group and 12 to an active control group. An analysis of covariance revealed that the experimental group had significantly greater increases (p < .05) on the chest press and leg press one-repetition maximum tests and the 6-min walk test from the baseline to postintervention compared with the control group. The experimental group correctly and independently performed a significantly greater number of steps of resistance training exercise tasks than the control group. Marginal significance and large effect sizes were found for the prone plank test and the stair climb test. The resistance training for empowerment was effective in promoting muscular strength and independent functional performance among adults with an intellectual disability.