The US Equal Employment Opportunity Commission said in the lawsuit filed in California Federal Court that since 2015, black workers at the Tesla plant have routinely been subjected to racist slurs and graffiti, including swastikas and nooses.
Tesla has failed to investigate complaints of racist conduct and has fired or otherwise retaliated against workers who reported harassment, the commission said in the lawsuit.
Tesla is already facing race discrimination lawsuits that make similar claims, including a class action by workers at the Fremont plant and a lawsuit by a California civil rights agency.
The company in those cases has said it does not tolerate discrimination and takes workers' complaints seriously.
The commission said in the lawsuit that it began investigating Tesla after the five-member panel's chairwoman, Charlotte Burrows, filed an internal complaint known as a charge against the company.
After finding last year that there was "reasonable cause" to believe Tesla had breached the federal law banning workplace race discrimination, the agency tried and failed to enter into a settlement agreement with the company, according to the lawsuit.
Ms Burrows in a statement said that fighting widespread workplace harassment is a key priority for the commission.
"Every employee deserves to have their civil rights respected, and no worker should endure the kind of shameful racial bigotry our investigation revealed,” she said.
The commission’s lawsuit seeks compensatory and punitive damages for an unspecified number of black workers, along with an order requiring Tesla to overhaul its policies prohibiting discrimination and retaliation.
The complaint comes as Tesla tries to fend off similar claims from the California Civil Rights Department, a state-level counterpart of the commission.
The department also alleges that Tesla discriminated against black workers when making decisions about pay, promotions and work assignments.
The department's lawsuit claims breaches of California law, while the commission's case involves federal laws.
Tesla has claimed that the California department's lawsuit was politically motivated.
It says the agency breached state law by suing without first notifying the company of all of the claims or giving it a chance to settle.
Tesla is also facing a class-action lawsuit in a California state court over the alleged mistreatment of black factory workers. About 240 workers have moved to join that lawsuit.