Football referees
Ricardo Mendoza
Ross Menzies
Ronnie Koh Min Kiat
Rachael Mitchenson
Retselisitsoe David Molise
Réka Molnar
Ricardo Montero
Reko Morikawa
Raj Palmson Moses
Robert Mosqueda
Ryo Munakata
Ross Murphy
Roxhers Muska
Robert Patrick Nagele
Robert Nagy
Rabee Naji
Redouane Necib
Răzvan Negară
Ross Nelson
Ricardo Ulises Norman Ortiz
R. Öberg
Rade Obrenović
Ricardo Ocampo
Rustam Omarov
R. Onyango
Rafael Orozco
Raúl Orozco Delgadillo
Ramón Ortega
Ronald Felipe Ortíz Otero
Ramdane Oukil
Rosendo Ovalle
Ramiro Andrés Pabón Martínez
Ricardo Andrés Pabón Reales
Roberto Carlos Padilla Tovio
Radoje Pajović
Roomet Pärn
Rulisa Patience Fidele
Rodrigo Pereira
Rodrigo José Pereira de Lima
Roberto Pérez Gutierrez
Romain Perpinan
Radu Petrescu
Renato Pinheiro
Riccardo Pinzani
Rok Jože Pirečnik
Roberto Ponis
Roman Potemkin
Renaud Potier
Radek Prihoda
Reon Radix