The 21-year-old joins the Clarets from Chelsea for an undisclosed fee, becoming the club's seventh addition under new manager Scott Parker.
Burnley reportedly fended off stiff competition from clubs across the Premier League and Europe to secure the highly rated midfielder's signature.
"It's a great feeling to sign for Burnley," said Ugochukwu, according to the club's official website.
"As soon as I was made aware of the club's interest in signing me, I was keen to hear more about the project. I spoke to the manager and Maxime (Esteve) - they were both so passionate about the club and the direction it's heading in.
"It feels like this is the perfect move for me at this stage of my career with the ambition the club is showing.
"It's a really exciting time to be here and I can't wait to get started. I'm really excited to pull on the Burnley shirt in the Premier League."
Ugochukwu arrived at Chelsea in the summer of 2023 from French side Rennes and signed a long-term deal at Stamford Bridge.
In his debut campaign with the Blues, he made 15 appearances - including six starts - before spending last season on loan at Southampton to gain further first-team experience.
Manchester United have firmly rejected Chelsea's attempts to secure winger Alejandro Garnacho through a swap deal, insisting on a cash-only transfer as they look to reshape their squad for the 2025-26 season.
Manchester City have reportedly launched a staggering 250 million pounds offer to bring Cole Palmer back from Chelsea, aiming to shatter the world transfer record and rectify a past oversight, according to reports.
Chelsea have set their sights on a daring move for Liverpool defender Ibrahima Konate, with reports from Spain suggesting the Blues are ready to test the Reds' resolve amid an injury setback in their own backline.
Nigeria and Bayer Leverkusen forward Nathan Tella has reportedly attracted interest from five Premier League clubs during this summer transfer window.
