Rainbow Springs was known as Wekiwa Creek by the Seminole Indians. Fishing for Mermaids in 1956. It was known as Blue Spring until the 1930s, when the site was developed as a tourist attraction and the promoter sought a more distinctive name (there are several other springs in Florida named Wekiwa and Blue).

The name "Rainbow Spring" or "Rainbow Springs" most commonly refers to Rainbow Springs State Park in Marion County, Florida. Historically, the area was known by the Seminole Indians as Wekiwa Creek, and later it was simply called Blue Spring until the 1930s. The name was changed to "Rainbow Springs" when developers transformed it into a private tourist attraction to compete with nearby Silver Springs, seeking a more distinctive and "colorful" name to market their submarine boat tours and "mermaid shows." It is a first-magnitude artesian spring that produces over 490 million gallons of crystal-clear water daily. In a completely different context, there was a famous wildlife park in Rotorua, New Zealand, also called Rainbow Springs, though it was officially rebranded and later closed/restructured in recent years. In Florida, the "Rainbow Springs" name has stuck for nearly a century and is now synonymous with the state park where visitors can swim, tube, and kayak down the Rainbow River. The springs are famous for their vibrant "rainbow-like" underwater colors caused by sunlight hitting the limestone and aquatic plants, making the 1930s marketing name a perfect fit for one of Central Florida's most beautiful natural landmarks.