 Ledecky akakwanisa kupinda mumakwikwi ekupedzisira emamita 800 emutambo weOlympic wakaitwa muLondon muna 2012kupfurikidza nokuisa wechitatu chose chose mumakwikwi ane nguva ya 8:23.84. Mumakwikwi ekupedzisira, Ledecky akashamisa munda, achikunda goridhe nemasekondi anopfuura mana, nenguva ye8: 14.63, iyo yaive yechipiri-yakakurumidza kuedza nguva dzese kumashure kwaRebecca Adlington rekodhi yenyika ye8: 14.10 yakaiswa muna 2008. Mukuwedzera, akaputsa chinyorwa cheAmerica chaJanet Evans cha 8:16.22 icho chakanga chakamira chibve muna 1989. Mumakwikwi okupedzisira, Ledecky akabuda nesimba uye, panosvika mamita 200, akanga atotanga kutungamirira anenge akareba muviri wake. 400-metre split yake yaiva 4:04.34, yakanakisisa yaLedecky pamurefu iwoyo, uye ingadai yakaiswa yechishanu mumunhu mumwe nomumwe 400-metre freestyle. Paakamhanya mamita 750, Ledecky akanga ari pamberi paMireia Belmonte García nemasekonzi 3,42 uye aiva pasi pemakwikwi epasi rose nemasekondi 0,31. Ledecky akakunda nemasekonzi 4,13 uye akadarika rekodhi yenyika nemasekonzi 0,53. Ndarama yake yaive menduru yekutanga yepasi rose yebasa rake, ichimupa iye 2012 Yakanakisa Mukadzi Kuita kweGore uye Breakout Performer yeGore paGolden Goggle Awards. 