Mitchell has played 26 times for Argyle in all competitions since joining the club on loan from Charlton Athletic in mid-August.
Head coach Tom Cleverley has confirmed that Mitchell will remain at Home Park for the remainder of the season after the deadline for the Addicks to recall the 24-year-old passed.
It is the fifth loan spell of the defender’s career, having gone to Bromley, Leyton Orient, St Johnstone and Lincoln City while at Millwall.
Signed by Charlton last season, he played 31 League One games as the Addicks won promotion to the Championship before finding himself at Plymouth.
Mitchell added that while being on loan can be disruptive, he has enjoyed the experience of playing for new teams in new places.
“I’ve been on loan a lot and I’ve always had speculation of what’s happening at the end of season and with January,” he said.
“I just look at one game at a time. I know it’s a bit cliche, but my first couple of loans at Leyton Orient and Bromley, I used to think, ‘If I keep doing well I’m going to put myself in the shop window,’ and stuff like that. But I think just one game at a time is the best approach and you can never get ahead of yourself.
“It’s not been great for my family, because they’ve travelled the whole country really, and the whole of the UK, to be fair.
“It’s a weird one because I love the loan system for me, personally. I think it’s been brilliant for me, I’ve got to see different places.
“I know loads of players who have just been at one club, stayed in London their whole life. I’ve played at different places in the country, so I’ve really enjoyed it off the pitch.
“On the pitch it probably is nice to be at a club for three years in a row, two years in a row, but I feel I’ve done well wherever I’ve gone so it’s maybe a good attribute to have to be able to settle into a team quick.”
