The area under the curve \( y = \cos x \) from \( x = 0 \) to \( x = \pi \) is given by the integral:
\[
A = \int_0^\pi \cos x \, dx
\]
The integral of \( \cos x \) is \( \sin x \), so:
\[
A = \left[ \sin x \right]_0^\pi = \sin \pi - \sin 0 = 0 - 0 = 2
\]
Thus, the area is 2 square units.