The former RAF officer was a member of a governmental review of early years education and a former expert member of a strategic committee within the Office of Deputy Prime Minister.
Turner said: "I truly believe the pathway for a positive UK economy is through world class skills at all levels. This, in turn, will provide positive global productivity, positive economic returns and provide true global mobility, all promoting the UK's standing as a world leader."
He added: "This new role as senior policy advisor at Semta provides a great platform for the sector to influence the skills policy in this vitally important sector at the heart of the industrial strategy.
"Through the industrial strategy, the government has officially recognised the central role advanced manufacturing and engineering will play in future economic growth; Semta's task is to ensure that skills policy is properly reflective of the needs of the sector so that it is able to grow."
Semta CEO Ann Watson said: "Stuart brings immense experience, energy and a new dynamic to Semta – he has hit the ground running."
Turner was group director, qualifications, standards and policy for SkillsActive, and was national director, professional standards for the National Childminding Association.
Semta (Science, Engineering, Manufacturing, Technologies Alliance) is a not for profit, employer-led skills organisation responsible for equipping the UK's vital engineering, science and manufacturing technologies sectors with the skills to compete on the global stage.
It represents 145,800 companies with a 1.66 million-strong workforce, which generates annual revenues of £321 billion.