Delivering an extra two million NHS operations, procedures and appointments a year in England was a central Labour manifesto pledge - and was included in a list of six first steps it would take in office.
The additional appointments were delivered in part by extra evening and weekend working, the government said.
Elective care covers a broad range of planned, non-emergency services, from diagnostic tests and scans to outpatient appointments, surgeries and cancer treatment.
There were 31.3 million operations, appointments and tests between July and November 2024, compared to 29.1 million over the same period in 2023, during which there were over a dozen days of junior doctors strikes.
The figures for the year up to July 2025, a year on from the election, will be closely scrutinised to see if this trend and the pledge have been borne out.
Ministers said NHS England data showed the manifesto commitment had been meet seven months early.
Sir Keir said the government was "not complacent" and knows "the job isn't done", as he promised further reforms to deliver faster treatment.
He unveiled plans in January to tackle the NHS backlog, which is one of the government's key missions.
The government has announced an extra £40m in funding for trusts who make the biggest improvements in cutting waiting lists, with the money available for hospitals from next year to spend on capital projects.