Edinburgh pair Josh Kerr and Jake Wightman joined Welsh runner Jake Heyward in making it through to Saturday's final after advancing through their semi-finals on Thursday.
It is the first time all three Team GB entrants have advanced to the men’s 1500m final since 1984.
Wightman took victory in the first semi-final in a time of 3:33.48 ahead of the USA’s Cole Hocker and gold medal favourite Timothy Cheruiyot from Kenya.
The second semi-final was won by Kenya’s Abel Kipsang in 3:31.65, setting a new Olympic record, with Norway’s Jakob Ingebrigtsen (3:32.13) second and Kerr third (3:32.18).
Heyward claimed a PB time of 3:32.82 to take sixth and qualify as one of the two fastest athletes not inside the top five.
All three win now compete for medals in the 1500m final due to take place at 12.40pm on Saturday.