Van Beijnen's contract runs through to 2021, with the 20-year-old's deal including a €100million buyout clause.
🔵🔴📝 We are delighted to announce that 20 year old Dutch defender Mike van Beijnen has signed a 2-year contract to join @FCBarcelonaB as a free agent.— FC Barcelona (@FCBarcelona) June 20, 2019
📋 Full details here: 👉 https://t.co/wFQXfdrmdX pic.twitter.com/ICaEeuQFGT
He arrives on a free transfer from NAC Breda and will link up with Barcelona B for the 2019-20 season.
Van Beijnen, who also spent time with Eredivisie giants PSV and Willem II, is reportedly the son of Frenkie de Jong's agent Ali Dursun.
Netherlands star De Jong agreed a €75m move to Barcelona from Dutch champions Ajax in January.
The 22-year-old midfielder is preparing for his first pre-season with Ernesto Valverde's side.