The 19-year-old joins the Heed having most recently spent time with Carlisle United after he joined the League Two side from Greek outfit Panegialios.
The centre-back, who is also adept on the left side of defence, makes his stay at Gateshead permanent after impressing whilst on trial with the club over recent weeks, appearing against both Consett and Harrogate Town.
Speaking to gateshead-fc.com after making the move permanent, Sakellaropoulos said: “I’m really happy.
“The manager and all of the staff have given me a good opportunity to play in the National League North for a great team with a great stadium.
“We’re a team who are aiming for promotion, it’s going to be hard but I think we’re a tough, strong team.”
Sakellaropoulos is raring to go ahead of the start of the new season this Saturday against Southport (kick-off 3pm), and is looking forward to developing under Mike Williamson’s guidance.
“I think for my age it will be to get experience in this league and play some games.
“You’re only going to get better with more games so if I get time on the pitch then that’s good for me.
“Pre-season was really good and I think we’ll get better day by day, it’s going to be a good season but a challenging one for me.
“We start on Saturday and I’ve been waiting for the start of the season to come, we’ll enjoy it and hopefully we’re going to win this game.”