The teachers wore wear pink to represent the "pink slips" expected to go out to more than 20,000 teachers statewide this year. Hundreds of those pink slips are slated to go to educators at San Diego County schools.
Friday's protests will take place along roadways and on freeway overpasses around the county.
Demonstrations were scheduled in Carmel Valley, San Marcos, Carlsbad, Oceanside, Fallbrook, Escondido, Ramona, National City, Chula Vista and San Diego, according to the California Teachers Association.
"I'm asking all Californians to wear pink (today) to show their support for our public schools," David Sanchez, president of the 340,000-member CTA, said in a statement.
According to the CTA, more than $11 billion in state education cuts were approved in the recent state budget.
"These cuts are going to hurt an entire generation of children and damage California's public education system for years to come," Sanchez said.
Today is the deadline for school districts to issue preliminary pink slips to teachers.
"The new state budget makes what is the largest single budget cut ever made to public education in California," said David Skinner, president of the Del Mar Teachers Association, where pink slips were given to 51 full-time and 24 temporary teachers.
"Our state already ranks 47th in education funding," he said. "These new cuts will impact an entire generation of children and escalate California's race to the bottom in education funding."