:2004 Canada Masters and the Rogers AT&T Cup

{{Short description|Combined WTA/ATP tennis tournament}}

{{Use mdy dates|date=January 2025}}

{{Infobox tennis event|2004|Canada Masters|

| date = July 26 – August 1 (men)
August 2–8 (women)

| edition = 115th

| category=Masters Series (ATP)
Tier I Series (WTA)

| surface=Hard / outdoor

| main_name = Canadian Open (tennis){{!}} Canadian Open

| location=Toronto, Ontario, Canada (ATP)
Montreal, Quebec, Canada (WTA)

| venue=Rexall Centre (ATP)
Uniprix Stadium (WTA)

| champms = {{flagicon|SUI}} Roger Federer{{cite web|title=2004 Toronto – Men's Singles draw|url=https://www.atptour.com/en/scores/archive/toronto/421/2004/draws?matchtype=singles|publisher=Association of Tennis Professionals (ATP)}}

| champws = {{flagicon|FRA}} Amélie Mauresmo

| champmd = {{flagicon|IND}} Mahesh Bhupathi / {{flagicon|IND}} Leander Paes{{cite web|title=2004 Toronto – Men's Doubles draw|url=https://www.atptour.com/en/scores/archive/toronto/421/2004/draws?matchtype=doubles|publisher=Association of Tennis Professionals (ATP)}}

| champwd = {{flagicon|JPN}} Shinobu Asagoe / {{flagicon|JPN}} Ai Sugiyama

}}

The 2004 Canada Masters and the Rogers AT&T Cup were tennis tournaments played on outdoor hard courts. It was the 115th edition of the Canada Masters, and was part of the ATP Masters Series of the 2004 ATP Tour, and of the Tier I Series of the 2004 WTA Tour. The men's event took place at the Rexall Centre in Toronto, Ontario, Canada, from July 26 through August 1, 2004, and the women's event at the Uniprix Stadium in Montreal, Quebec, Canada, from August 2 through August 8, 2004.

The men's draw was headlined by World No. 1, Australian Open and Wimbledon champion Roger Federer, Wimbledon finalist and recent Indianapolis titlist Andy Roddick, and French Open runner-up and Monte Carlo winner Guillermo Coria. Other top seeds were 2004 Rome Masters champion Carlos Moyá, Indian Wells runner-up Tim Henman, David Nalbandian, Juan Carlos Ferrero and Rainer Schüttler.

The women's field was led by WTA No. 2, Rome and Berlin winner Amélie Mauresmo, Roland-Garros champion Anastasia Myskina, and French Open runner-up Elena Dementieva. Among other top players present were former World No. 1 Jennifer Capriati, seventeen-year-old Wimbledon champion Maria Sharapova, Ai Sugiyama, Nadia Petrova and Paola Suárez.