"Welcome Iniesta", Emirates Club said on messaging platform X, formerly known as Twitter.
The club, based in Ras Al-Khaimah, posted a photograph of Iniesta wearing their shirt and said the terms of the contract would be announced at a press conference on Wednesday.
The veteran left the Japanese club Vissel Kobe last month after five years.
Iniesta won nine LaLiga titles with Barcelona and four Champions League titles. With Spain, he won the 2010 World Cup and back-to-back Euro titles in 2008 and 2012.
After leaving Barcelona in 2018 he joined Vissel Kobe and led the club to their first title the following year, winning the Emperor's Cup, as well as reaching the semi-finals of the AFC Champions League in their first appearance in the continental competition.
