Welder Santos was born in Brasilia, Brazil on May 29th, 1992. At the age of four, his family moved from Brazil to the United States in pursuit of a better lifestyle. He grew up in South Florida and played both basketball and soccer in high school.

During his first year in college he decided to pursue acting as a career which led him to appearances in commercials for Nikon, KFC, Party City and more. His interest in acting was sparked when his family encouraged him to give it a try while he was still in school and working towards his degree. He began focusing his training at the Acting School of South Florida and took a theatre class at Palm Beach State College. It wasn't long after he began training that he got booked for his first role. He first made an appearance in a French directory assistance commercial for "118218". Followed by that the doors opened and many more opportunities flourished his way. He has been steadily building up a great body of work and has also performed on the stage as well.