Partington had been serving as interim chief executive of the WSTA before the arrival of its new head Miles Beale last month.
Partington said: “I am delighted to be joining the BSDA team and I look forward to supporting its members and the soft drinks industry.
“The association has an enviable reputation and I hope to build on its success in ensuring the industry’s voice is heard.”
Before joining the WSTA, Partington worked as director of communications at the Lawn Tennis Association and was a one-time political editor of GMTV.
BSDA president David Saint said: “His experience of the media and dealing with public policy issues will be invaluable to us and I look forward to working with him over the next few years.”