To solve the inequality \( x - 5 \leq -6 \), we can isolate \( x \) by adding 5 to both sides:
\[ x - 5 + 5 \leq -6 + 5 \]
This simplifies to:
\[ x \leq -1 \]
So the solution to the inequality is:
\[ x \leq -1 \]
Thus, the correct answer is:
\( x \leq -1 \).