As a country drives efforts in establishing adolescent/youth friendly services to cater to the unique reproductive and sexual health of adolescents/youths, it is pertinent that the youth know about these services to be able to access and benefit from them. This study therefore examined the knowledge of youths on available adolescent/youth friendly services (A/YFRHS) in Ikeja, Lagos State, Nigeria. The study was a descriptive cross-sectional survey that collected data from 427 (15 to 24) year olds. Respondents answered questions on general knowledge of A/YFRHS, Sources of knowledge about A/YFRHS, Services offered by A/YFRHS facilities and identification of locally available A/YFRHS. Data were analyzed using SPSS version 21 to generate descriptive statistics. Two hundred and twenty-eight (82%) of the respondents had general knowledge about A/YFRHS. More than half, 268 (79.5%) of the respondents did not know of a specific A/YFRHS provided in study area. Friends/peers (45.7%) were the best source of information on A/YFRHS. The most popular services known were family planning (81.6%), voluntary counselling and testing (73.8%), and sexually transmitted diseases (67.3%). Knowledge was low (SE = 0.11; SD = 2.20) with a mean score of 5.46 on a 10-point scale. The participants knew what adolescent/youth friendly services were but did not know where to get these services from because they were not aware of the available A/YFRHS facilities. Extensive awareness of locally available A/YFRHS is needed in the study area.