The figure is the highest since records began in 2007.
NHS waiting lists in England have climbed to a new record high of 7.6 million.
Data published by NHS England on Thursday revealed 7.6 million people were waiting to start treatment at the end of June, up from 7.5 million in May.
The figure is the highest since records began in 2007.
A total of 383,083 people had been waiting more than 52 weeks to start routine hospital treatment at the end of June, down slightly from 385,022 at the end of May.
Elsewhere, some 7,177 patients are estimated to have been waiting more than 18 months, down from 11,446 at the end of May.
The Government and NHS England vowed to eliminate all waits of more than 18 months by April 2023 – excluding exceptionally complex cases or patients who choose to wait longer – with the aim of stopping waits of more than a year by March 2025.
The publication of the figures comes after the NHS announced that patients affected by backlogs could skip the queue at their local hospital if they are willing to travel to other parts of England.
The health service is extending the use of a “matching platform” where patients are “matched” with providers of the service they need outside their local area.
The system was initially launched in January for patients needing a hospital admission, but will now include cancer, diagnostic checks and outpatient appointments.
Earlier this month the Government also revealed it would expand its use of private sector capacity in a bid to ease pressure on the NHS.
Thirteen new community diagnostic centres (CDCs) will open across England, eight of which will be privately run. The facilities will carry out an additional 742,000 scans, checks and tests per year.
Health Secretary Steve Barclay said: “We must use every available resource to deliver life-saving checks to ease pressure on the NHS.”
Prime Minister Rishi Sunak has made cutting waiting lists one of his priorities for 2023, pledging in January that “lists will fall and people will get the care they need more quickly”.
However, he has said strikes across the health service are making the task “more challenging”.
Industrial action has been ongoing since December 2022 in the NHS, leading to the postponement of almost 835,000 appointments.
Junior doctors are set to stage their fifth strike in the dispute on Friday, walking out for four days from 7am. Consultants will strike for two days from August 24, and have threatened to walk out for a further 48 hours on September 19 if the Government continues to “refuse to agree to pay talks”.
In July, the Government said all public sector workers will get a pay rise in line with pay review body recommendations.
Junior doctors will receive 6%, as well as an additional £1,250 consolidated rise, while consultants will be given 6%.
Mr Sunak said “there will be no more talks” on pay and that the Government’s proposed deal is “fair”.
