Oklahoma is about 289 times bigger than Saint Lucia.

Saint Lucia is approximately 616 sq km, while Oklahoma is approximately 177,847 sq km, making Oklahoma 28,771% larger than Saint Lucia. Meanwhile, the population of Saint Lucia is ~167,122 people (3.6 million more people live in Oklahoma).
Tip: This to-scale comparison of Saint Lucia vs. Oklahoma uses the Mercator projection, which distorts the size of regions near the poles.