Pedro Diogo Tavares Martins de Oliveira (born January 1, 1988) is a Portuguese swimmer, who specialized in backstroke and butterfly events.

Oliveira competed at the 2005 and 2006 European Junior Swimming Championships in Budapest, Hungary and in Palma de Mallorca, Spain, where he earned two silver medals each in the 200 m backstroke.

[7][8] At the 2008 European Aquatics Championships in Eindhoven, Netherlands, Oliveira experimented with the 200 m butterfly, where he posted a lifetime best of 1:59.00 in his semifinal run, sinking Diogo Carvalho's Portuguese record by 0.67 of a second.

[9] Four months later, at the 2008 Summer Olympics in Beijing, Oliveira failed to reach the top 16 in any of his individual events, finishing twenty-fourth (with a new national record) in the 200 m butterfly (1:57.41), and twenty-eighth in the 200 m backstroke (2:01.08).

In the 200 m butterfly, Oliveira broke a new Portuguese record of 1:56.17 to secure his semifinal spot with an advantage of a polyurethane swimsuit, slashing off Carvalho's standard by a 0.65-second deficit.

[16] Oliveira also competed for Portugal at the 2011 Summer Universiade in Shenzhen, China, where he placed ninth in the 200 m butterfly at 1:58.50, just missing out the final by a small fraction of a second.