Tadej Valjavec (born 13 April 1977 in Kranj) is a Slovenian former professional road bicycle racer, who last competed for the Sava team.

On 4 May 2010 Valjavec's name was released as being one of several riders under investigation by the UCI for "irregular blood values".

Team manager Vincent Lavenu stated that should the Slovenian cycling federation sanction him, he would be fired.

[2] Valjavec has proclaimed his innocence and claimed an unreported illness is responsible for the values.

[4] On 22 April 2011 The Court of Arbitration for Sport set aside the decision to exonerate the athlete from any doping offense and imposed a two-year ban on him starting on 20 January 2011, as well as the disqualification of all his results obtained between 19 April and 30 September 2009.