Adams, who joins the Whites from Bundesliga side RB Leipzig, joins for an undisclosed fee and has penned a five-year deal at Elland Road, running until the summer of 2027.
The 23-year-old began his career with New York Red Bulls and was handed his MLS debut by current Leeds head coach Jesse Marsch in April 2016, against the San Jose Earthquakes. The duo were later reunited in Europe last season when Marsch was manager of Leipzig.
Meanwhile, fellow new signing Sinisterra also arrives at Elland Road for an undisclosed fee and has penned a five-year deal, running until the summer of 2027.
The 23-year-old joins from Eredivisie outfit Feyenoord for whom he made 49 appearances in all competitions last season, helping them finish third in the Eredivisie and reach the UEFA Conference League final.
The Colombian had a fine individual season, scoring a huge 23 goals for Feyenoord whilst he also laid on 14 assists.
At the end of the last campaign, he was named the Europa Conference League Young Player of the Season and was also selected in the Europa Conference League Team of the Season.
“I am very happy to be here in this beautiful club, I am enjoying this time,” Sinisterra told LUTV Speaking after signing for Leeds.
“I know it’s a historic club with beautiful fans. I heard a lot of things about the stadium and atmosphere, it’s amazing, so I can’t wait to feel that in person.
“It was my dream when I was a child [to play in the Premier League]. Right now, I am close to making that.”