Beales, who has spent much of his career working for Government offices, will take over from interim chief executive Gavin Partington in June.
WSTA Chairman Tim How said: "I am very pleased to welcome Miles to the WSTA. He brings with him extensive experience across Government, which will help the industry navigate a broad range of policy issues impacting the sector at both UK and EU level."
Beales said he was looking forward to the new role and supporting its members and the wine and spirit industry. "Together we can chart an effective course between responsibility, growth and consumer choice," he said.
The WSTA has been led by communications director Partington since the departure of former chief executive Jeremy Beadles last November.