The formula for the volume \( V \) of a square-based pyramid is given by:
\[ V = \frac{1}{3} \times \text{Base Area} \times \text{Height} \]
Given that the area of the base is 12 square units and the height is 15 units, we can substitute these values into the formula:
\[ V = \frac{1}{3} \times 12 \times 15 \]
First, calculate \( 12 \times 15 \):
\[ 12 \times 15 = 180 \]
Now, substitute this result back into the volume formula:
\[ V = \frac{1}{3} \times 180 = 60 \]
Thus, the volume of the pyramid is:
\[ \boxed{60} \text{ cubic units} \]