Finding the list of Cities in Mindanao online was not easy as I thought it would be. I had to confirm each of the city compiled in this Wikipedia link.
I found a cities of Mindanao list in this website, it has only 27 cities, it was not updated. So, I had to make my own list.
This tally of mine has 29 Mindanao Cities, and this is useful for travelers, or for students for their research.
Bayugan
Bislig
Butuan
Cabadbaran
Cagayan de Oro
Cotabato
Dapitan
Davao
Digos
El Salvador
Gingoog
Iligan
Isabela
Kidapawan
Koronadal
Lamitan
Malaybalay
Marawi
Mati
Oroquieta
Ozamis
Pagadian
Samal
Surigao
Tacurong
Tagum
Tangub
Valencia
Zamboanga