Björn Gustaf von Sydow (born 26 November 1945) is a former speaker (talman) of the Riksdag, the Swedish parliament.

Apart from leading the Riksdag sessions, von Sydow was also while in office eligible to serve as acting-regent (Riksföreståndare) in the absence of the King and his three children, e.g. if they all went abroad simultaneously, although that never happened.

However, when Göran Persson asked for his resignation after the lost 2006 election, the parliamentary situation was very clear, so already on 19 September 2006 Sydow could formally ask Fredrik Reinfeldt to begin the formation of a new government to take office after the new Riksdag has assembled to approve it.

On 2 October 2006, the changed majority situation in the Riksdag also had Sydow replaced by Moderate Party politician and previous Vice Speaker Per Westerberg.

Already before the election, Sydow had stated that he was not interested in a Vice Speaker position, so that office went to fellow Social Democrat Jan Björkman.