The 2003 CA-TennisTrophy was a tennis tournament played on indoor hard courts at the Wiener Stadthalle in Vienna in Austria and was part of the International Series Gold of the 2003 ATP Tour. The tournament ran from October 6 through October 12, 2003.
Roger Federer defeated Carlos Moyá 6–3, 6–3, 6–3
- It was Federer's 7th title of the year and the 15th of his career.
Yves Allegro / Roger Federer defeated Mahesh Bhupathi / Max Mirnyi 7–6(9–7), 7–5
- It was Allegro's only title of the year and the 1st of his career. It was Federer's 8th title of the year and the 16th of his career.