2004 BA-CA-TennisTrophy

{{TennisEventInfo|2004|BA-CA-TennisTrophy|

| date=11–17 October

| edition=30th

| category=International Series Gold

| prize_money=$658,000

| draw=32S / 16D

| surface=Hard / indoor

| location=Vienna, Austria

| venue=Wiener Stadthalle

| champs= {{flagicon|ESP}} Feliciano López{{cite web|title=2004 Vienna – Singles draw|url=https://www.atptour.com/en/scores/archive/vienna/337/2004/draws?matchtype=singles|publisher=Association of Tennis Professionals (ATP)}}

| champd= {{flagicon|CZE}} Martin Damm / {{flagicon|CZE}} Cyril Suk{{cite web|title=2004 Vienna – Doubles draw|url=https://www.atptour.com/en/scores/archive/vienna/337/2004/draws?matchtype=doubles|publisher=Association of Tennis Professionals (ATP)}}

| before_name=CA-TennisTrophy

| main_name=Vienna Open

}}

The 2004 BA-CA-TennisTrophy was a tennis tournament played on indoor hard courts. It was the 30th edition of the event known that year as the BA-CA-TennisTrophy, and was part of the International Series Gold of the 2004 ATP Tour. It took place at the Wiener Stadthalle in Vienna, Austria, from 11 October through 17 October 2004.