A citizen reported the leak at about noon Tuesday coming from the pipeline off the 101 Freeway. The pipeline, owned by Santa Maria-based Plains All-American Pipeline, was on land, and the oil flowed from land into the ocean.
The pipeline was later secured and the leak was stopped, Santa Barbara County Office of Emergency Management officials said.
The U.S. Coast Guard was monitoring clean-up operations. A commercial oil spill response company has begun clean-up, Coast Guard officials said.
Santa Barbara County Office of Emergency Management, Exxon, the Santa Barbara County Fire Department and California Department of Fish and Wildlife were on scene.
The public was urged to avoid the area during clean-up.