The 69-year-old also managed the Blues on a temporary basis for the final three months of the 2008-2009 campaign.
The Dutchman left his role as Netherlands Manager during their unsuccessful European qualifying campaign.
Chelsea sacked Mourinho seven months after he led them to the Premier League title.
The 52-year-old Portuguese had been in his second spell at the club as the Blues are currently 16th on the EPL table.
Chelsea finished eight points clear last season and also won the League Cup, but have endured a terrible start to their defence, losing nine of their 16 league games so far.