The top 10 included a wide cross-section of brands from different sectors, with mobile brand Giffgaff in third followed by three charities: Cancer Research UK, the British Red Cross and ARKive.
Cadbury, ASOS, The Ellen DeGeneres Show and the Met Office rounded out the top 10.
The Social Brands 100, created by social agency Headstream, was whittled down from a crowd-sourced list of more than 300 nominated brands. These were then scored by social-media monitoring firm Brandwatch and a panel of industry judges, which included Twitter's UK head of sales, Bruce Daisley.
Innocent's success reflects its continued investment in social media and the strong showing of FMCG brands overall. Last year, the smoothies brand came in seventh, when Dell topped the list.
Innocent was praised by judges for its consistent tone of voice and ability to engage with consumers across channels.
Joe McEwan, communities manager, at Innocent, said: 'We've always wanted to build relationships with our drinkers. It started with talking to people on our packaging, inviting them to call the 'Bananaphone' and meeting them at events we put on. It naturally extended into digital and social media as the channels evolved.'
Other brands that made the top 100 include Tetley, Wonga, Ford and Marmite.
For the full list, visit Brand Republic's The Wall blog at Wallblog.co.uk
Video produced by Sarah Johnson. Follow @BRproducers