https://en.wikipedia.org/wiki/George_Welch_(pilot)
In his book Aces Wild: The Race for Mach 1 (1998), fellow North American test pilot Al Blackburn speculates that Welch may have broken the sound barrier two weeks before Yeager in an early flight of the XP-86 prototype. Welch himself never made that claim. Blackburn based his contention on interviews of eyewitnesses, former North American employees and access to contemporary historical accounts.Robert Kempel, author of The Race For Mach 1 contradicts the claim, contending it was impossible for Welch’s aircraft to break the sound barrier with an underpowered engine. He notes that the XP-86 airframe was capable of transonic flight, but the interim low-power J35-C-3 limited its performance. The late Bob Hoover, chase pilot for Welch and Yeager, had also disputed the Welch story, stating that Welch was not flying that day because his plane was being repaired.[12] The highest Mach number reached by Welch in 1947, as indicated by official flight test records, was about 0.93, in a maximum power dive from 45,114 ft (13,751 m) with the engine at 100.8-percent Military RPM (i.e. maximum power). North American conducted this test, their “High Mach Number Investigation”, on November 13. The USAF verified all North American results and this test Mach number in their own Phase II tests conducted in December 1947.
By the end of 1947, the XP-86 had logged 29 hours and 23 minutes of flight test time, most flown by Welch.[14] On October 14, 1947, Captain Charles Yeager exceeded Mach 1 in the Bell X-1. The claim of the XP-86 passing Mach 1, with Welch at the controls, was not made until April 26, 1948, five and a half months after the X-1 supersonic flight. Blackburn, however, maintains that a record on the Muroc radar theodolite, of the two flights Welch made on November 13, 1947 indicated supersonic flights, as well, noting 20 minutes before the X-1 broke the record, a sonic boom was heard over the desert, centered on the Happy Bottom Riding Club, dude ranch restaurant and hotel operated by Pancho Barnes.
That sounds like there is a possibility that Welch did it first but the odds favor Yeager.
Seeing the name, Bob Hoover reminds me that he was the one who described Yeager as “the best”.
Interestingly, in his book, Yeager said that the guy they call “Ridley” had waxed him in a mock dog fight.