The 54-year-old, known as "Everest Man", reached the summit for the 29th time earlier this month, before climbing to the top again.
"Kami Rita reached the summit this morning. Now he has made a new record with 30 summits of Everest," Mingma Sherpa of Seven Summit Treks, his expedition organiser, told AFP.
A guide for more than two decades, Sherpa first stood on the 8,849-metre (29,000-foot) peak in 1994 when working for a commercial expedition.
Since then he has climbed Everest almost every year, guiding clients.
"I am glad for the record, but records are eventually broken," he told AFP after his 29th climb on May 12.
"I am more happy that my climbs help Nepal be recognised in the world."
Last year, Sherpa climbed Everest twice to reclaim his record after another guide, Pasang Dawa Sherpa, equalled his number of ascents.
Kami Rita Sherpa previously said that he has been "just working" and did not plan on setting records.
He has also conquered other 8,000-metre peaks including the world's second-highest mountain, K2 in Pakistan.
Romanian climber dies
His success on reaching the top came as the season's death toll climbed to five.
A Romanian climber died during a bid to scale Lhotse, the fourth-highest mountain, his expedition organiser said.
"He was found dead in his tent on Camp Three on Monday morning by his guide," said Mohan Lamsal of Makalu Adventure, naming the climber as Gabriel Viorel Tabara.
Everest and Lhotse share the same route until diverting at 7,200 metres.
"We are making efforts to bring his body down," he said.
Earlier this week, two Mongolian climbers went missing and were later found dead after summiting Everest.
Two more climbers, one French and one Nepali, have died this season on Makalu, the world's fifth-highest peak.
Nepal has issued more than 900 permits for its mountains this year, including 419 for Everest, earning more than $5 million in royalties.
Around 500 climbers and their guides have already reached the summit of Everest after a rope-fixing team reached the peak last month.
This year, China also reopened the Tibetan route to foreigners for the first time since closing it in 2020 because of the pandemic.
Nepal is home to eight of the world's 10 highest peaks and welcomes hundreds of adventurers each spring, when temperatures are warm and winds typically calm.
Last year more than 600 climbers made it to the summit of Everest but it was also the deadliest season on the mountain, with 18 fatalities.
