Bauer Media, which operates the main regional franchises, cited a 10% growth in the reach of its Clyde 1 station since last summer.
The industry figures, known as RAJAR, reported that April to June saw an annual rise for Clyde 1 to 643,000 listeners for part of the average week.
That was the highest share of the radio market since 2004.
The total number of hours during which people listened to the station, which covers west central Scotland, was up by nearly 7% to almost five million hours in total.
Forth 1, covering east central Scotland, had 366,000 listeners in the average week, up 5%, and representing nearly 18% of listeners in the area. It saw a rise of nearly half in the number of hours of listening.
Tay FM had 135,000 listeners, and achieved a market share of 21%, its highest since 2011.
There was a similar market share for MFR, based in Inverness, and Westsound, covering south-west Scotland.
Graham Bryce, managing director of Bauer City Network, said: "These fantastic results demonstrate our ongoing commitment to, and passion for, local radio across Scotland.
"Our station talent, along with our rich heritage of over 40 years in this sector, guarantee an unparalleled understanding of the market which is particularly reassuring for listeners in times of uncertainty.
"Continuing to grow our listener figures in such a competitive space is a real achievement and allows our advertisers to access highly-engaged and relevant local audiences."
The RAJAR figures were up for Capital and Heart FM stations.
The commercial sector has to compete for audiences with the BBC, from which Radio 2 has continued to have the biggest reach in Scotland.
The industry figures, based on a continuing survey of a sample of radio listeners, found that BBC Radio Scotland continued to reach more than a fifth of adults in Scotland.
At 20.5% of the audience, that means 929,000 listeners in the average week listening for an average of six hours and 14 minutes.
The head of Radio Scotland, Jeff Zycinski, said the share of the audience had remained stable, but that "time spent with the station, or hours per listener, seems to have taken a bit of a dip".
He linked this to the end of the football season, and said there would be a marketing effort to increase the retention of audiences through the listening day.
Scotland's main commercial radio broadcaster has welcomed significant increases in listener figures.