The flag of England is white with a red cross. This red cross is also known as St. George's Cross.
According to the reference, the Flag of England is white with a red cross (St George's Cross) on it. It is flown at sporting events and as a show of English nationalism. St George's Cross is an element of the more familiar Union Jack, the national flag of the United Kingdom. So while St. George's Cross is part of the United Kingdom's flag, the standalone white flag with a red cross specifically represents England.
Therefore, England's flag is white with a red cross (St. George's Cross). While the Union Jack, the flag of the United Kingdom, incorporates St. George's Cross, the question asks about a flag that is white with a red cross, which is the flag of England.
