Turner's appointment as marketing, communications and services director follows the departure of marketing director Kirsten Ford, who is returning to her native New Zealand. Ford was responsible for Freeserve's current £10m TV campaign.
Freeserve has also appointed Jonathan Saverimuttu as head of advertising.
He joins from HSBC Bank following the departure of Talia Webb last month.
As well as being responsible for all above-the-line activity and an advertising spend of £15m, Turner will take responsibility for Freeserve's direct marketing activity, which has not previously been under the marketing director's remit.
Freeserve consumer managing director Keith Hawkins said this recognised how important direct marketing will be to the ISP as it prepares to end its multi-million-pound distribution deal with Dixons.
"Direct marketing is very important to us and we definitely see more customers coming through that channel in the future," he said.
The restructure comes as Freeserve readies itself for a rebrand under the name of French parent Wanadoo.
To increase competition on its narrowband rivals, Freeserve is introducing a special price offer in the run-up to Christmas. From this weekend, three months' flat-rate access will be half price (£7.49 a month).