The appointment will take effect after Nopporn resigns from his current post and signs an employment contract with GPO.
Nopporn is well known for his role in advancing tobacco control measures, including a policy proposal to enlarge the health graphic warnings to cover more than 85 per cent of cigarette packets, and campaigning for a ban on asbestos.
The GPO top post had been vacant since November after the GPO board sacked director Dr Suvaj Siasiriwattana because he was unable to solve internal conflicts and the agency missed targets under his administration.