The surface area \( A \) of a sphere can be calculated using the formula:
\[ A = 4\pi r^2 \]
where \( r \) is the radius of the sphere.
The diameter of the sphere is given as 30 inches, so the radius \( r \) is half of the diameter:
\[ r = \frac{30}{2} = 15 \text{ inches} \]
Now, plug the radius into the surface area formula:
\[ A = 4\pi (15)^2 \] \[ A = 4\pi (225) \] \[ A = 900\pi \text{ in}^2 \]
Thus, the surface area of the sphere is:
\[ \boxed{900\pi} \text{ in}^2 \]