The County Magazine will be distributed to 21,000 select homes in the two counties and is also available by subscription.
It features star interviews, high-end fashion, top beauty tips, luxury interiors and gardens and exotic holidays.
The first edition, with a May cover date, was distributed on 19 April.
It is fronted by Yeovil-born TV star Sarah Parish who gave an exclusive interview to the magazine, taking about a recent role opposite Hollywood star Kevin Costner.
Extracts of the interview, in which Sarah reveals for the first time how her teenage years in Yeovil set her on course for a successful acting career, are reproduced in the Western Gazette and Mid Somerset Series newspapers on April 19 to promote the magazine.
The lifestyle magazine also contains an interview with TV fashion guru Gok Wan.
Sarah Pullen, managing director of Western Gazette Media, said: "The launch of The County Magazine fills me with both pride and excitement.
"This fantastic monthly product encapsulates a lifestyle that we all aspire to. Readers will be entertained, educated and inspired in equal measure.
"And uniquely we can guarantee customers that the magazine will be read by the people that they are determined to reach."
