Oxford United have been majority owned by Indonesian investors Anindya Bakrie and Erick Thohir since late 2022.
“The Club has strong ties with Indonesia and through our continuous conversations, we were made aware of Marselino’s ability,” Buckingham added.
“While unproven at this level, it is clear that Marselino is extremely talented with good international experience, and it will be exciting to see how he adapts to life at Oxford United.”
Marselino, who has over 3.9 million Instagram followers, started his career in Indonesia with Persebaya Surabaya.
“Being the first Indonesian-born player to play in the Championship if selected fills me with immense pride,” he said.
The U’s travel to Blackburn Rovers in the Championship on Saturday.