Both players had been out of contract since the end of the interrupted 2019/20 season.
Their previous deals had been due to expire on June 30 but they agreed short-term extensions to take them to the end of the campaign when fixtures were rearranged following the coronavirus stoppage.
Now the club have moved to secure their services for the forthcoming season.
Former England defender Jagielka, 38, rejoined the Blades on a free transfer at the beginning of last season after a 12-year spell at Everton. He made 10 appearances in all competitions for Chris Wilder’s side during the campaign.
Former Everton, Manchester City and Sunderland midfielder Rodwell, 29, made two appearances after signing for the club in January.
Manager Wilder told the club’s website, www.sufc.co.uk: “Phil is a valuable and respected member of the squad and I’m delighted to keep him in the building for next season.
“The same applies with Jack, who offered us versatility and gave us options within the group during the second half of last term.”