- England
- France
- Ireland
- Scotland
- Wales
{{main|1991 Five Nations Championship}}EnglandHead coach: Geoff Cooke - Paul Ackford
- Rob Andrew
- Will Carling (c.)
- Wade Dooley
- Jerry Guscott
- Nigel Heslop
- Richard Hill
- Simon Hodgkinson
- Jason Leonard
- Brian Moore
- Jeff Probyn
- Dean Richards
- Mike Teague
- Rory Underwood
- Peter Winterbottom
- England used the same 15 players in the four games
FranceHead coach: Daniel Dubroca - Abdelatif Benazzi
- Pierre Berbizier
- Serge Blanco (c.)
- Xavier Blond
- Laurent Cabannes
- Didier Camberabero
- Marc Cécillon
- Denis Charvet
- Christophe Deslandes
- Jean-François Gourragne
- Thierry Lacroix
- Jean-Baptiste Lafond
- Patrice Lagisquet
- Grégoire Lascubé
- Philippe Marocco
- Pascal Ondarts
- Olivier Roumat
- Philippe Saint-André
- Philippe Sella
- Michel Tachdjian
IrelandHead coach: Ciaran Fitzgerald - Jack Clarke
- Keith Crossan
- David Curtis
- Des Fitzgerald
- John Fitzgerald
- Neil Francis
- Mick Galwey
- Simon Geoghegan
- Gordon Hamilton
- Kenneth Hooks
- Michael Kiernan
- Phillip Matthews
- Brendan Mullin
- Kenny Murphy
- Brian Rigney
- Brian Robinson
- Rob Saunders (c.)
- Brian Smith
- Steve Smith
- Jim Staples
ScotlandHead coach: Jim Telfer - John Allan
- Gary Armstrong
- Paul Burnell
- Craig Chalmers
- Damian Cronin
- Chris Gray
- Gavin Hastings
- Scott Hastings
- John Jeffrey
- Sean Lineen
- Kenny Milne
- Alex Moore
- David Sole (c.)
- Tony Stanger
- Derek Turnbull
- Derek White
WalesHead coach: Ron Waldron - Paul Arnold
- Chris Bridges
- Alun Carter
- Tony Clement
- John Davies
- Phil Davies
- Ieuan Evans
- Steve Ford
- Glenn George
- Scott Gibbs
- Mike Griffiths
- Neil Jenkins
- Arthur Jones
- Robert Jones
- Paul Knight
- Emyr Lewis
- Gareth Llewellyn
- Glyn Llewellyn
- Martin Morris
- Paul Thorburn (c.)
- Brian Williams
{{DEFAULTSORT:1991 Five Nations Championship Squads}} 1 : Six Nations Championship squads |