Moyles, who announced last month that he will hand over the Breakfast reigns to evening presenter Nick Grimshaw, saw his audience fall to 6.93m listeners in the second quarter of this year (April 2 - June 24).
The Chris Moyles Show lost more than half a million listeners year-on-year, falling below the seven million mark for the first time since the end of 2006. Moyles's figures were down from the previous quarter's 7.10m and from 7.44m in the same period last year.
However, Radio 2's breakfast star Chris Evans was also hit by a drop in ratings in the second quarter, after nearly 300,000 listeners departed the programme over the three months.
The Chris Evans Breakfast Show drew a weekly audience of 8.95 million listeners - down from last quarter's near-record of 9.23m but up on last year's 8.67m.
Overall, Radio 1 reached 11.27 million listeners every week in the second quarter, up on last quarter's 11.14m but down on the 11.69m in the same period last year. The station's audience share of 8.3% was up slightly from last quarter's 8.2%.
Radio 2's weekly audience hit 14.46 million, a drop on the record 14.56m last quarter, but considerably up on the 13.97m last year. The station had a share of 16.1%, down from last quarter's 16.8%, but a big rise on last year's 14.9%.
It may have been mixed news for the BBC's main stations, but the digital spinoffs fared much better in the quarter.
Radio 4's spinoff digital-only station Radio 4 Extra, which specialises in entertainment programmes from the BBC Archive, enjoyed a record weekly audience of 1.64m listeners over the period, up from 1.5m last quarter and 1.61m last year.
Radio 1's sister station 1Xtra drew in 1.14m listeners, the biggest total since the station was launched ten years ago.
Continuing its strong performance since it was saved from closure, Radio 6 Music attracted 1.38m listeners weekly, up from 1.27m last year, but down slightly on last quarter's record 1.45m.
BBC Radio 5 live sports extra climbed above 1m listeners, pulling in a weekly audience of 1.07m, up from 797,000 last year and 952,000 last quarter.
All four of the BBC digital-only networks now reach more than a million listeners each.
According to new figures supplied by measurement body RAJAR, radio listening via digital platforms now accounts for 31.5% of all radio consumption, including internet radio increasing to 4.6% of the total.
In total, all BBC Radio stations reached 34.44 million people every week, down on 34.59m from last quarter and from 35.53m last year. The overall audience share of 54.3% was down from 55.4% last quarter but up from 54% last year.
"These figures represent a strong performance across our portfolio and an industry in robust health," said Tim Davie, the director BBC Audio & Music.
"Last year we laid out a clear strategy for our digital stations, so it is great to see our digital-only networks breaking records and all four attracting more than a million listeners every week."
Also in the RAJAR figures for the BBC, Radio 3 attracted 2.04m weekly listeners in the second quarter, a strong increase on the previous quarter's 1.9m but well down on the 2.17m last year.
Radio 4 also saw a year-on-year decline, as its weekly audience of 10.52m was down by 300,000 on the 10.85m in the same period in 2012. However, the station did rally on last quarter's 10.31m.
Despite the start of the BBC's 'summer of sport, Radio 5 Live could only muster a weekly audience of 6.15m, down both on last quarter's 6.36m and last year's 6.54m. Combined with 5 Live Sports Extra, the station had an overall reach of 6.36m.
The BBC Asian Network was roughly flat at 547,000 weekly listeners compared to last quarter's 540,000, while the BBC World Service slightly increased its weekly reach to 1.39m from 1.3m in the previous quarter.
BBC Local / Regional radio reached 8.96 million listeners per week - from 9.9m last quarter and 9.65m last year.
Chris Moyles's career at Radio 1 in pictures:
Copyright: Rex Features