The former England defender barely featured for Chelsea last term, running his contract down so that he could pick his next destination from the offers available. Fulham were linked with him in January, while a return to Burnley, with whom he spent time on loan in the 2004-05 campaign, had also been mooted.
However, on Monday it was confirmed he has moved south of the river, crossing the Thames to take up a two-year contract under Roy Hodgson at Selhurst Park. Cahill is just the club's third summer acquisition, following the deals for Stephen Henderson and Jordan Ayew.
Hodgson required a fresh central defensive option with Scott Dann no longer the force he was and Martin Kelly likely to feature at right-back following the departure of Aaron Wan-Bissaka to Manchester United.
After a tough final season at Stamford Bridge, where he featured just eight times under Maurizio Sarri, Cahill could take a while to get fully fit. Saturday's season-opener at home to Everton is likely to come too soon but a debut before the end of the month is realistic.
Palace's season may hinge on whether the Toffees manage to force through their proposed move for Wilfried Zaha but it could still be a long campaign for Hodgson's men even with the Ivorian. Having Cahill around would ease the burden and at 33, he knows the game.
A glance down his CV makes for impressive reading, with two Premier Leagues, a couple of FA Cups, the Champions League and two Europe League titles amongst his haul. Add to that the 61 caps he earned for England and we are talking about a serious campaigner.
Cahill will bring, experience, composure, leadership and a willingness to put his head in where it hurts. All of these are qualities that could prove vital to an Eagles team who could struggle to soar in 2019-20.