Mr Keating, who was in his 50s, died in a car crash near Swinford in Co Mayo on Saturday, a collision in which his wife Annemarie was injured.
Members of Cork City FC, which Ciaran Keating’s son Ruairi plays for, as well as representatives of the Marie Keating Foundation cancer charity, were among the mourners.
Marie Keating was diagnosed with breast cancer in September 1996, and died less than 18 months later in February 1998 aged 51.