Upson signs for Stoke
The 32-year-old, who played in the 2010 World Cup and has been capped 21 times by England, left West Ham United following their top-flight relegation last season.
Upson will link up with former England centre back Jonathan Woodgate, who joined the FA Cup runners-up last month after an injury-ravaged spell at Tottenham Hotspur.
"This is another fantastic deal for this football club when you consider the quality and experience of the lad and the fact that he is a free transfer," Stoke manager Tony Pulis said in a statement.
"We now have strength in depth in our defence with both Matthew and Jonathan on board and we've managed to achieve that without a significant outlay on transfer fees, which is quite remarkable in today's market of vastly inflated prices."