To simplify the expression \( \frac{x^{675}}{x^{453}} \), we can use the property of exponents that states \( \frac{x^a}{x^b} = x^{a-b} \).
So, we have:
\[ \frac{x^{675}}{x^{453}} = x^{675 - 453} = x^{222} \]
Thus, the simplified expression is:
\[ \boxed{x^{222}} \]