The Manchester United star has come under heavy fire in recent days after scoring an own goal while playing for England against Scotland.
It follows his start against Ukraine on Saturday night, which drew criticism from fans due to his bit-part role for United in recent months.
But some criticism has turned nasty and Maguire's mother Zoe has since responded on social media.
She wrote: "As a mum seeing the level of negative and abusive comments in which my son is receiving from some fans, pundits and the media is disgraceful and totally unacceptable to any walk of life never mind someone who works his socks off for club and country."
Maguire has been at the centre of a storm of criticism throughout the season and United boss Erik ten Hag has relegated him to fifth-choice centre-back at Old Trafford.
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West Ham were keen on signing the centre-back in the summer but he insisted he wanted to stay put and fight for his spot.
The former Leicester star has played just 23 minutes of football this season, coming on as a sub against Arsenal in a match that United lost 3-1.
But he admitted he did not want to leave just yet at United despite his first-team chances decreasing.
He said: "We just didn't come to an agreement and they were happy for me to stay and I was happy to fight for my place.
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"I want to do that and every time I train or play, I will give everything. At club football, I want to play games, I want to play football.
"The first four weeks were hard because it was one game a week and the manager didn't select me but we have lots of games coming up now and I am sure I will play lots of games."
It led to bemusement from fans and pundits alike when Gareth Southgate called Maguire up to his England squad this month, and further still when he started against Ukraine.
But when he came on against Scotland and scored an unfortunate own goal, there was outright vitriol levelled at the defender.
That included from within the stadium at Hampden Park on Tuesday night, from home and away fans.
Maguire's mum continued: "I was there in the stand as usual, it's not acceptable what's been created, over nothing. I understand that in the football world there are ups and downs, positives and negatives but what Harry receives has gone far beyond "football".
"For me seeing him go through what he's going through is not ok. I would hate to have to see any other parents or players go through this in the future, especially the young boys and girls breaking through the ranks today.
"Harry has a massive heart and it's a good job he's mentally strong and can handle it as others may not be able too. I wish this sort of abuse on nobody!"