There are about as many anthologies with "Canada" or "Canadian" in their titles as there are anthologies with "American" or "English," roughly 30, per database queries of isfdb. The most comprehensive modern anthologies of Canadian science fiction are two compiled by American editor David G. Hartwell and Canadian editor Glenn Grant. Their first volume focused on familiar genre writers, while the second adds unexpected (at the time) authors like Margaret Atwood and Robertson Davies.
A decade later, Robert J. Sawyer's book focused on both active writers and on award-winning stories, with an appendix of stories and novels that have won any awards for science fiction or fantasy.
Most reprinted authors: James Alan Gardner, Nalo Hopkinson, Robert J. Sawyer, Peter Watts, and Robert Charles Wilson, with 3 each.
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Northern Stars: The Anthology of Canadian Science Fiction, David G. Hartwell & Glenn Grant, eds. (Tor, 1994)
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Northern Suns: The New Anthology of Canadian Science Fiction, (Tor, 1999)
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Distant Early Warnings: Canada's Best Science Fiction, (Robert J. Sawyer Books, 2009)
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Combined Contents by Author and Title
Jean-pierre April
Rêve Canadien
(Tesseracts Q, 1996)
-- Northern Suns
Margaret Atwood
Freeforall
(The Toronto Star Weekly Sep 20 1986)
-- Northern Suns
Alain Bergeron
The Eighth Register
(Tesseracts Q, 1996)
-- Northern Suns
Robert Boyczuk
Doing Time
(Erotica Vampirica, 1996)
-- Northern Suns
Joël Champetier
Soluble-Fish
(Solaris #59 1985)
-- Northern Stars
Eric Choi
Divisions
(Tesseracts 6, 1997)
-- Northern Suns
Lesley Choyce
The Loneliness of the Long-Distance Writer
(Orion v1 #2 1982)
-- Northern Stars
Carolyn Clink
Stars
(The Stars As Seen from This Particular Angle of Night, 2003)
-- Distant Early Warnings
David Clink
Copyright Notice, 2525
(Asimov's Dec 2006)
-- Distant Early Warnings
John Clute
Fables of Transcendence
(Out of This World, 1995)
-- Northern Suns
Michael G. Coney
The Byrds
(Changes, 1983)
-- Northern Stars
Julie E. Czerneda
Bubbles and Boxes
(New Voices in Science Fiction, 2003)
-- Distant Early Warnings
Robertson Davies
Offer of Immortality
(Twilight Zone Jul 1982)
-- Northern Suns
Charles de Lint
Pity the Monsters
(The Ultimate Frankenstein, 1991)
-- Northern Stars
Cory Doctorow
Craphound
(Science Fiction Age Mar 1998)
-- Northern Suns
Candas Jane Dorsey
(Learning About) Machine Sex
(Machine Sex and Other Stories, 1988)
-- Northern Stars
Dave Duncan
Under Another Moon
(Tesseracts 3, 1990)
-- Northern Stars
Pat Forde
In Spirit
(Analog Sep 2002)
-- Distant Early Warnings
James Alan Gardner
Ars longa, vita brevis
(Nature Nov 9 2000)
-- Distant Early Warnings
The Ray-Gun: A Love Story
(Asimov's Feb 2008)
-- Distant Early Warnings
The Reckoning of Gifts
(Tesseracts 4, 1992)
-- Northern Stars
William Gibson
The Winter Market
(Vancouver Nov 1985)
-- Northern Stars
Phyllis Gotlieb
Mother Lode
(F&SF Nov 1973)
-- Northern Stars
Glenn Grant
Memetic Drift
(Interzone #34 1990)
-- Northern Stars
Terence M. Green
The Woman Who Is the Midnight Wind
(Tesseracts, 1985)
-- Northern Stars
Wesley Herbert
Twilight of the Real
(On Spec Win 1997)
-- Northern Suns
Nalo Hopkinson
A Habit of Waste
(Fireweed #53 1996)
-- Northern Suns
Men Sell Not Such in Any Town
(Nature Sep 15 2005)
-- Distant Early Warnings
A Raggy Dog, a Shaggy Dog
-- Distant Early Warnings
Jan Lars Jensen
Domestic Slash and Thrust
(Tesseracts 5, 1996)
-- Northern Suns
Eileen Kernaghan
Carpe Diem
(On Spec Fll 1989)
-- Northern Stars
Nancy Kilpatrick
Farm Wife
(The Vampire's Crypt #5 1992)
-- Northern Suns
W. P. Kinsella
Things Invisible to See
(On Spec Win 1994)
-- Northern Suns
Scott MacKay
The Sages of Cassiopeia
(F&SF Dec 1994)
-- Northern Suns
Sally McBride
The Fragrance of Orchids
(Asimov's May 1994)
-- Northern Suns
Yves Meynard
Stolen Fires
(Edge Detector #3 1991)
-- Northern Stars
Charles Montpetit
Beyond the Barriers
(Prairie Fire Sum 1994)
-- Northern Suns
Derryl Murphy
The History of Photography
(Prairie Fire Sum 1994)
-- Northern Suns
David Nickle
The Dummy Ward
(TransVersions #1 1994)
-- Northern Suns
John Park
Retrieval
(Tesseracts 2, 1987)
-- Northern Stars
Ursula Pflug
Bugtown
(TransVersions #6 1996)
-- Northern Suns
Claude-michel Prevost
Happy Days in Old Chernobyl
(Tesseracts 3, 1990)
-- Northern Stars
Garfield Reeves-Stevens
Outport
(Ark of Ice, 1992)
-- Northern Stars
Spider Robinson
User Friendly
(Tales from the Planet Earth, 1986)
-- Northern Stars
You Don't Know My Heart
(Stars: Original Stories Based on the Songs of Janis Ian, 2003)
-- Distant Early Warnings
Esther Rochon
Xils
(Tesseracts 2, 1987)
-- Northern Stars
Geoff Ryman
Fan
(Interzone Mar 1994)
-- Northern Suns
Robert J. Sawyer
The Abdication of Pope Mary III
(Nature Jul 6 2000)
-- Distant Early Warnings
Just Like Old Times
(On Spec Sum 1993)
-- Northern Stars
Shed Skin
(The Bakka Anthology, 2002)
-- Distant Early Warnings
Karl Schroeder
Halo
(Tesseracts 5, 1996)
-- Northern Suns
-- Distant Early Warnings
Daniel Sernine
Stardust Boulevard
(Tesseracts, 1985)
-- Northern Stars
Michael Dennis Skeet
Near Enough to Home
(Arrowdreams, 1998)
-- Northern Suns
Heather Spears
One
(Tesseracts 2, 1987)
-- Northern Stars
Jean-Louis Trudel
Remember, the Dead Say
(Tesseracts 4, 1992)
-- Northern Stars
Élisabeth Vonarburg
Home by the Sea
(Tesseracts, 1985)
-- Northern Stars
Peter Watts
The Eyes of God
(The Solaris Book of New Science Fiction Volume Two, 2008)
-- Distant Early Warnings
A Niche
(Tesseracts 3, 1990)
-- Northern Stars
Repeating the Past
(Nature Nov 29 2007)
-- Distant Early Warnings
Andrew Weiner
Distant Signals
(Twilight Zone May/Jun 1984)
-- Northern Stars
Robert Charles Wilson
Ballads in 3/4 Time
(F&SF Apr 1987)
-- Northern Stars
The Cartesian Theater
(FutureShocks, 2006)
-- Distant Early Warnings
The Great Goodbye
(Nature Sep 21 2000)
-- Distant Early Warnings