Porter, 30 was initially signed by former manger Danny Wilson in July 2011 but following the end of his Bramall Lane contract this summer has signed a years extention. He was top scorer last season with 11 goals.
Meanwhile Davies, 33 who joined the Blades on loan from Derby County in the later stages of last season was instrumental in helping the club reach the FA Cup semi-final as well as finishing a respectable 7th place in the league.
Blades boss Nigel Clough told sufc,co.uk; "Chris and Ben are well known to the coaching staff and we're delighted that they are on board for next season. Both contributed to our success last season and we hope they will do the same when we kick off the new campaign."