Catharina "Tini" Wilhelmina Wagner (17 December 1919 – 2 June 2004) was a freestyle swimmer from the Netherlands, who represented her native country at the 1936 Summer Olympics in Berlin, Germany.

In 1936 she won the gold medal in the 4 × 100 m freestyle relay, alongside Willy den Ouden, Rie Mastenbroek and Jopie Selbach. In the 100 m freestyle competition she finished fifth and in the 400 m freestyle event she finished seventh.

• Tini Wagner's profile at the Dutch Olympic Committee^{[permanent dead link]} (in Dutch)
• Tini Wagner at Olympics at Sports-Reference.com (archived)