Events kick off on Friday, with the weather forecast looking promising - a balmy 25C. However, some rain and thunder showers are forecast over the weekend.
19 areas (or 'islands') are sponsored by radio stations, newspapers and other companies and 11 stages play host to musicians from a broad range of genres.
Anastacia and Natalie Imbruglia will perform on the Wien Energie/Ö3 stage on Saturday. German singer-songwriter Andreas Bourani is Friday's highlight. He will be supported by Austria's Christina Stürmer, Tagträumer and the Makemakes.
Highlights on the FM4 stage, which showcases alternative rock and pop acts, include Wanda, Nazar, Thees Uhlmann, Skero, Fritz Kalkbrenner, Yasmo & Die Klangkantine, Chicks on Speed and OK Kid.
Minisex, Harry Ahamer & Band and Opus will appear on the Wien Energie/Radio Wien stage.
DJ Ötzi, Petra Frey, Marc Pircher & Band, Marco Ventre & Band, Udo Wenders, Middle Of The Road and the Nockalm Quintett will play the Radio Niederösterreich Schlager & Oldies stage.
Fans of electronic music should look out for Swedish DJ AronChupa, da:herbst & Florian Hereno, The Chainsmokers, Danny La Vega, Deejay Selecta and Rene Rodriguez.
There's also a cabaret, sport and children's programme, and numerous catering stands offering international cuisine.
The Donauinselfest costs around €4 million to stage and although all the concerts are free Vienna's economy is estimated to benefit by almost €40 million due to the increased tourism.
For more information check out the festival website.