In addition to Newsom, other defendants listed in the suit include California Department of Public Health Director Dr. Sonia Angell, Los Angeles County Sheriff Alex Villanueva, and Los Angeles County Public Health Director Dr. Barbara Ferrer.
The suit came after Villanueva announced Thursday that due to Newsom's executive order, not all gun and ammunition stores in Los Angeles County are considered important businesses and must be close to the public.
"There are hundreds of businesses that, for no fault of their own, do not fall within the governor's definition of critical infrastructure," Villanueva said this week. "As a result, I have instructed my deputies to enforce closures of businesses that have disregarded the governor's orders (gun shops, strip clubs and other non-designated businesses)."
Newsom's order allows grocery stores, gas stations, pharmacies and other businesses to stay open during the stay-at-home order, but forces the closure of others considered insignificant.
The lawsuit filed by the NRA and other gun owner groups claims the executive order violates gun owners by their other amendment rights.
"The circumstances of the outbreak of the novel Coronavirus (" COVID-19 ") are remarkable, but do not excuse unlawful violations of liberty," the suit states.
"In fact, the importance of maintaining the ongoing business of important California, plaintiff, safety, health and welfare businesses is the point: the need for increased security during uncertain times is precisely when plaintiffs and their members must be able to exercise their fundamental rights to to hold and carry weapons. "
The Los Angeles County Sheriff's Department said it had not yet been served with the lawsuit and had no comment. Proponents of Newsom, Ferrer and Angell did not immediately return CNN's requests for comment.
"In this time when we all need to sacrifice to flatten the curve and stop this pandemic, it is worrying that the NRA will not turn away from its overall purpose – to increase the profits of the profit industry at all costs," said Brady President Kris Brown.
"There is no constitutional right to spread coronavirus while shopping, for weapons or anything else."
CNN's Kevin Bohn contributed to this report.