The former Doncaster Rovers youngster earned a senior contract after impressing the Shields management team in training over recent weeks.
McGowan, 18, was part of Sunderland’s academy from the age of 12 to 16 before his stint with Doncaster, where he regularly trained with the first-team as he displayed significant progression.
He said: “I’m really excited to have joined the club.
“I’ve been training for a while and now I just want to get going and play games.
“There’s a great group of lads here and they’ve made me feel really welcome since I came in.
“It feels like the club is going places and it’s something I want to be part of.”
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