Philippe Seydoux (born 23 January 1985) is a Swiss professional ice hockey defenceman currently playing for SC Langenthal in the Swiss League (SL) on loan from fellow SL club, EHC Kloten.

His play attracted the attention of the NHL's Ottawa Senators, who drafted him in the third round (100th overall) in the 2003 NHL Entry Draft.

He then moved to EHC Kloten where he played with the Kloten junior team as well as part-time with the professional team.

He became a full-time member of the professional team in 2004.

[1] On 29 July 2019, with one-year remaining on his contract in his second stint with EHC Kloten, Seydoux was loaned to fellow league competitors and former club, SC Langenthal, for the duration of the 2019–20 season.