At the age of 20, Clelia Tini was entering the Olympic Games for the first time and was the only athlete to represent San Marino in swimming competition at the London Olympics. She qualified for the Games by using a universality place from swimming's world governing body FINA because her fastest time of 58.12 seconds was 1.58 seconds slower than the "B" (FINA/Olympic Invitation) qualification time for her event, the women's 100 metre freestyle. Tini set herself the goal of lowering her personal best and go below under 58 seconds, "I am very excited but I am also very charged. I am aware that I have prepared very well and have all the credentials to make a race in line with my expectations." She was drawn in heat three on 1 August, placing eighth and last of all swimmers with a time of 58.29 seconds. Tini was 38th overall and she could not advance into the semi-finals as her effort was 3.86 seconds off the slowest competitor who made the later stages. After the event, she declared her happiness over her performance and revealed her preparation for the Olympics were hindered by a back injury.