João Diogo made his Primeira Liga debut with the Madeirans on 13 January 2012, playing the full 90 minutes in a 1–1 away draw against F.C.
João Diogo spent the first part of the following campaign on the sidelines, nursing an injury.
[9] In January 2018, João Diogo joined CS Gaz Metan Mediaș of the Romanian Liga I.
[10] On 7 February of the following year he signed with FCV Farul Constanța in the same country (Liga II), owned by former Romanian international Ciprian Marica.
[11] João Diogo represented Portugal at under-21 level, appearing for the nation at the 2009 Lusofonia Games.