The club broke the news on its official website on Wednesday and also revealed that there will be an option for them to sign the Muangthong United player on a permanent basis.
Almeria CEO Jose Juan Bonillo and sporting director Alberto Benito will fly to Thailand on February 18 to tie up the final details of the deal with the Thai Premier League (TPL) side.
Described on the website as an "Asian football star" who had the necessary physical attributes, Almeria also claimed that there was interest from fellow La Liga side Atletico Madrid and English Premier League giants Manchester City.
"He can play as the main reference point up front, as a second striker, as an attacking midfielder and on either wing," Almeria added.
"He has great quality on the ball, he is quick, skillful and has great vision, which allows him to assist his team-mates as well as score."The 25-year-old Teerasil spent two weeks training with Atletico back in January last year and had made no secret of his ambition to play in Europe. The stint was extended to a full month after he caught the attention of the coaching staff and there was talk that Teerasil would be signed by Atletico, although no deal was finalised in the end.
The Bangkok native, who has scored over 100 goals in the Thai leagues and has 29 goals in 58 caps for the War Elephants, is widely regarded as one of the best strikers in Southeast Asia.