de Marigny served as an assistant coach of A-League side Melbourne Victory from 2013 to 2015,[1][2] departing on 22 May 2015 to return home to Sydney to be with family and support his wife Donna who underwent breast surgery for cancer.
[3][4] On 18 June 2015, de Marigny was announced as assistant coach of the Newcastle Jets, under Scott Miller.
[7] On 6 June 2018 Western Sydney Wanderers announced that de Marigny was joining the club to take over the vacant assistant coach position.
On 10 March 2021, de Marigny returned to Melbourne Victory as an assistant coach.
[10] After leaving Melbourne he has subsequently had stints returning back to the Wanderers, with the Australian Women's national team and the Lambton Golden Eagles in various coaching roles.