Chris Evans helped Virgin Radio overcome the barrier of one million listeners, Rajar's last show.
His new breakfast show attracted an average weekly audience of 1.05 million in the first three months of 2019.
Before joining Virgin Radio, the average was around 480,000 listeners.
Evans moved to Virgin in January after leaving BBC Radio 2, where he attracted about nine million listeners during his decade on the breakfast show.
The DJ said he moved to Virgin because "he wanted a new mountain to climb", adding: "I returned to my spiritual home and I love every minute of it".
The new host of the Radio 2 breakfast show, Zoe Ball, has kept the audience relatively stable in its first three months of work.
He recorded 9.05 million listeners in the first quarter of this year – only 18,000 fewer than in the last series of Evans figures.
Ball said she was "super excited" about the figures and thanked the listeners "for giving us a chance and for getting so involved in the antics of the show".
There has been a noticeable increase in news and station listeners in the three months prior to the UK scheduled departure date from the European Union at the end of March.
About 364,000 extra listeners tuned in to BBC Radio 4's Today program, bringing its average weekly audience to 7.16 million.
Also the BBC Radio 5 Live show's breakfast rose by 214,000 listeners to 2.14 million.
Similarly, the LBC commercial news station celebrated the highest reach of its 47-year history, with 2.25 million weekly listeners on average.
Elsewhere, the host of Radio 1 breakfast, Greg James, fell slightly, by 67,000 listeners, to 5.04 million.
The breakfast show Kiss also saw a dip of about 50,000 listeners, at 1.7 million nationwide, after the departure of Rickie, Melvin and Charlie, who spent a decade with the station.
By Steven McIntosh, BBC News show reporter
Given the number of program changes recently recorded on the radio, this is the most significant Rajar district for some time.
But, as always, the raw numbers do not give us the complete picture.
First, Zoe Ball and Chris Evans have not yet technically completed the so-called "full book" (the neighborhood begins at New Year's Eve and Ball did not start his show until January 14th, while Evans started on January 22nd).
It is also worth noting that many station heads worry more about total hours than coverage, particularly in commercial radios, where more advertising can be sold depending on how long listeners are tuning in to.
Some of the big radio beasts are completely missing from this quarter's figures. For example, Simon Mayo's new show is absent from the latest Rajar data.
This is due in part to the fact that the former presenter of Radio 2 entered a brand new station, La Scala, which was launched only in March and will not produce any results until the end of the year.
But even if we had data for Scala, we would not have the figures for the Mayo show in particular because it hosts the mid-morning slot and Rajar only publishes the data for programs and breakfast stations in general.