Subject to a medical, the 30-year-old central midfielder, who made his professional debut at 17, is the latest addition to an overhauled Roar squad.
Roar’s new recruit spent the majority of his career in La Liga with Celta Vigo, before recent spells at Spanish second-tier club Real Valladolid and English Championship side Sheffield Wednesday.
Coach John Aloisi today said he was delighted to add more talent to his squad.
"Alex is a very technically-gifted player who will suit our high-tempo playing style. I am delighted he has chosen to sign for our club," Aloisi said.
Lopez heads Down Under following a lengthy career in a number of Europe’s top leagues and joins Brisbane following a 2017-18 season in Spain with Sporting Gijon.
"Having played at the highest level in Spain for many seasons, I am confident he will be a great addition to our midfield,” Aloisi said.
"After arriving in Brisbane this morning, I encourage all our members, supporters, and the local football community to come and meet Alex in person at our pre-season match this Saturday night at our City of Logan training facility.”