The Barcelona academy graduate is the latest arrival in this summer's Saints revamp.
Southampton FC (@SouthamptonFC) August 12, 2015
His move comes after two successive seasons out on loan to Valencia and Stuttgart, and adds further depth to a midfield recovering from the loss of Morgan Schneiderlin.
Romeu performed well in his time away from Stamford Bridge and is the type of tidy but combative midfielder that will slot in comfortably alongside Steven Davis, Victor Wanyama and fellow new arrival Jordy Clasie.
It’s been another season of upheaval for the Saints - following the losses of Toby Alderweireld, Nathaniel Clyne and the aforementioned Schneiderlin - but they appear to have come out of it well once again.
Reaction on Twitter from both sets of fans was strong, with a general consensus that Southampton may have bagged themselves yet another bargain:
If Romeu turns out half as good as Bertrand then we've got a great signing there. Just need that last CB now...— Fraser (@frasercoppin) August 12, 2015
Romeu will be wanted by top clubs next season, mistake selling him.— Matt (@Mattshack16) August 12, 2015
Always like Romeu, think he'll do well for Southampton— Josh Gibbons (@gibbo199O) August 12, 2015
Romeu will be such a class signing for saints,— matt martin (@mrMattmartin) August 12, 2015
Romeu a good deal, but another short contract?! Should be 4 minimum. #saintsfc— The Archers Road End (@ArchersRoadEnd) August 12, 2015
Romeu signing adds a bit of steel to our Midfield - quite a limited player but good cover for Wanyama #saintsfc— Paul Arnold (@ArnieTTR) August 12, 2015
I love it when we sign players out the blue. Romeu has always looked like a decent player. #SaintsFC— Richard Brereton (@bagel_buns) August 12, 2015
As many have said, Romeu showed good signs as part of AVB's Chelsea, and if anyone can help him thrive it will be #SaintsFC.— Dominic Nozahic (@domnozahic) August 12, 2015
I really never understood the hype about Romeu under AVB, bit of a jack of all trades master of none kinda player. Hope he does well tho.— Miles (@_MilesTweets) August 12, 2015