The 18-year-old Ecuadorian defender arrives to reinforce Juliano Belletti's side in the Segunda Federación after the two clubs finalised terms roughly a week ago, with Monday's announcement confirming the last details had been ironed out.
Caicedo is an attacking left-back with strong physical attributes and an explosive change of pace, and he can also operate further forward as a left winger, fitting the sporting department's push to source talent from beyond La Masia.
This season marked Caicedo's breakthrough at LDU Quito's first team, where he featured in both the Ecuadorian league and the Copa Libertadores. The buy option included in the loan is reported to be worth around €2.5m, with LDU also retaining a sell-on percentage should Barcelona make the move permanent and later sell the player on.
Barcelona will be hoping the teenager continues his development at Atlètic level with a view to triggering that clause next summer.
Belletti, a World Cup winner with Brazil in 2002 and a former Barcelona right-back himself, takes charge of a Barça Atlètic side building for another push in the fourth tier of Spanish football. Caicedo's arrival adds further depth and versatility to the back line, with the club continuing to look at South American markets as part of a broader recruitment strategy that extends beyond the traditional academy pipeline at La Masia.
LDU Quito paid tribute to Caicedo on social media as the move was confirmed, thanking him for his contribution and wishing him well in Europe, where he becomes the latest in a line of young Ecuadorian players to move to the continent in recent years.
The teenager will link up with Barça Atlètic's squad for pre-season training in the coming days as he begins the process of adapting to Spanish football at the club's Ciutat Esportiva Joan Gamper training complex.