Kammala wannan jumla: A cikin wasansa na biyu a ranar 9 ga Agusta, 200-mita butterfly, ya zama dan wasa na farko a tarihi don yin wasan karshe a cikin wannan taron, bayan ya gama 5th a 2000, 1st a 2004 da 2008, kuma na biyu a 2012. (Federica Pellegrini zai zama dan wasa na biyu da zai yi haka a gasar Olympics ta 2020.) A Rio, ya lashe kambin da ya rasa ga Chad le Clos shekaru hudu da suka gabata a London, yana cin Masato Sakai da 0.04 s. Phelps ya bayyana cewa lashe wannan lakabi shine babban burin lokacin dawowarsa. An gabatar da farko da na karshe na wannan taron sosai a matsayin sakewa tsakanin Phelps da Le Clos. Dangantaka tsakanin Le Clos da Phelps ya kasance mai kyau a cikin 2012<unk>13 amma ya lalace a cikin 2014 lokacin da Phelps ya dawo daga ritaya kuma ya nuna cewa lokutan malam buɗe ido na yanzu suna da jinkiri. A cikin dakin shirye-shiryen kafin tseren farko, damben inuwa na Le Clos yayin da Phelps "ya haskaka a kusurwa" ya haifar da meme na Intanet tare da hashtag #PhelpsFace. Har ma an lalata tarihin Wikipedia na Le Clos bayan wasan karshe. A lokacin da yake da shekaru 31, nasarar ta sanya Phelps ba kawai zakara ba ne kawai, amma har ma da zakara mafi tsufa a tarihin wasan Olympics, wanda ya doke rikodin da Duke Kahanamoku ya kafa a shekarar 1920, da kuma Inge de Bruijn a shekara ta 1920.
2004 daidai da haka. Phelps kuma ya zama dan wasa na farko da ya lashe lambar zinare na mutum a cikin shekaru 12. Anthony Ervin ya karya waɗannan bayanan biyu bayan kwana uku.