The men's 100 metre backstroke event at the 1948 Olympic Games took place between August 4 and 6, at the Empire Pool. This swimming

Swimming (sport)

Swimming is a sport governed by the Fédération Internationale de Natation .-History: Competitive swimming in Europe began around 1800 BCE, mostly in the form of the freestyle. In 1873 Steve Bowyer introduced the trudgen to Western swimming competitions, after copying the front crawl used by Native...

 event used the backstroke

Backstroke

The backstroke, also sometimes called the back crawl, is one of the four swimming styles regulated by FINA, and the only regulated style swum on the back. This has the advantage of easy breathing, but the disadvantage of swimmers not being able to see where they are going. It is also the only...

. Because an Olympic size swimming pool is 50 metres long, this race consisted of two lengths of the pool.

Medalists

Semifinals

Rank	Athlete	Country	Time	Notes
1	Allen Stack Allen Stack Allen McIntyre Stack was an American backstroke swimmer, who won the 100m Backstroke at the 1948 Summer Olympics in London.-References:*...		1:07.3	Q

Key: Q = qualification by place in heat, q = qualification by overall place

Final

Rank	Athlete	Country	Time	Notes
	Allen Stack Allen Stack Allen McIntyre Stack was an American backstroke swimmer, who won the 100m Backstroke at the 1948 Summer Olympics in London.-References:*...		1:06.4
	Robert Cowell Robert Cowell Robert Elmer "Bob" Cowell was an American backstroke swimmer from Pennsylvania. Cowell won a silver medal at the 1948 Summer Olympics in London. Cowell was a United States naval officer.-References:...		1:06.5
	Georges Vallerey		1:07.8
4	Mario Chávez Mario Chávez Mario Chávez is an Honduran association footballer who plays as a defender for C.D.S. Vida.-External links:*...		1:09.0
4	Clemente Mejía		1:09.0
6	Jackie Wiid		1:09.1
7	John Brockway John Brockway (swimmer) William John Brockway was a former British swimmer and captain of the British swimming team at the 1952 and 1956 Olympic Games. He was born in Bristol and died in Newport....		1:09.2
8	Bert Kinnear		1:09.6