The 2003 CA-TennisTrophy was a men's 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. It was the 29th edition of the tournament and took place from 6 October until 12 October 2003. First-seeded Roger Federer won the singles title.
See main article: 2003 CA-TennisTrophy – Singles. Roger Federer defeated Carlos Moyá 6–3, 6–3, 6–3
See main article: 2003 CA-TennisTrophy – Doubles. Yves Allegro / Roger Federer defeated Mahesh Bhupathi / Max Mirnyi 7–6(9–7), 7–5