The aim of the study is to assess the level and degree of swimming skills among swimmers in sports and marathon swimming distances at the Olympic Games at the I-III stages of their holding from 1896 to 2016. The object of the study: monitoring the performance of elite swimmers at the Olympic Games in distance sports and marathon swimming. The subject of the study: monitoring the dynamics of the results of swimming skills formation in swimmers-winners at all Olympic Games in distance sports swimming at the I-II-III stages of their holding. The summarized official competition protocols for all the past Olympic Games at the I-II-III stages of the Olympic Games from 1896-1948, 1952-1992 and 1996-2016 for men (193+420+300=913) and women (75+388+300=763). The state-of-the-world and comparative experiment identified age and average speed in the achievements of men and women swimmers at different distances to determine the degree of reliable formation of swimming skills at the level of (р=< > 0,05). At the I stage of the Olympic Games from 1896-1948, the levels of some difference in the age of men and women medalist swimmers (difference of age: men, x±m=22,40±0,88; women, x±m=19,20±0,32; t=0,002; р>0,05). Absolute values of the average speed of swimming showed a gradual decrease in the difference rates among men and women from the increase in distance and swimming methods: some difference in average speed of about – 0,17 m/s (men, x±m=1,35±0,14; women, x±m=1,18±0,10; t= 0,033; р>0,05). A detailed analysis of the results for the II stage of the Olympic Games from 1952-1992, showed the age features of swimmers-winners. The lowest difference for average speed was represented in freestyle swimming – 400-800-1500 m to – 0,15 m/s; in medley swimming 200-400 m – 0,15 m/s; to – 0,16 m/s in breaststroke 100-200 m swimming; on the backstroke up to – 0,17 m/s at 100-200 m; and at 100-200 m butterfly – 0,18 m/s, at distances of 50-100-200 m freestyle – 0,23 m/s; in relay swimming – 0,24 m/s (difference of average swimming speed – 0,17 m/s: men, x±m=1,70±0,15; women, x±m=1,53±0,11; t=1,768; р>0,05). At the III stage of the Olympic Games from 1996-2016, the age features of the swimmers-winners have been clarified: the difference in age of men and women is noted at the level of 2-3 years (difference of age: men, x±m=23,76±0,98; women, x±m = 22,82±0,91; t= 0,010; р>0,05). The smallest difference registered in marathon swimming at 10000 m – 0,08 m/s; stayer freestyle – 400-800-1500 m at the level – 0,12 m/s; medley swimming 200-400 m/s – 0,14 m/s; breaststroke at 100-200 m to – 0,16 m/s; backstroke up to – 0,18 m/s per 100-200 m, as well as in swimming 100-200 m butterfly – 0,18 m/s; relay swimming – 0,20 m/s. Meanwhile, the greatest difference in swimming in the 50-100-200 m freestyle – 0,21m/s. The general difference between all the results of the swimmers in the formation of swimming skills at these competitions from 1996-2016, was revealed at the level – 0,17 m/s (difference of average speed of swimming, m/s: men, x±m=1,81±0,16; women, x±m = 1,64±0,12; t=7,19; р<0,05).