Al Ettifaq midfielder Henderson was jeered during England’s 1-0 win over Australia at Wembley on Friday.
Henderson captained England, with Harry Kane rested, but was booed when he was replaced by Kalvin Phillips in the second half.
He completed a controversial switch to Al Ettifaq from Liverpool in the summer having been a vocal supporter of LGBTQ+ rights, with homosexuality illegal in Saudi Arabia, but former Anfield team-mate Elliott has backed the 33-year-old.
“It’s upsetting, Hendo is a massive inspiration, not just to myself but to many around the world,” said the Liverpool midfielder. “For what he has done for England and English football it’s not nice to see.
“It’s his decision, it’s his career. As a nation we need to get behind these players and support them. It wasn’t nice, but knowing Hendo I’m sure it hasn’t fazed him.
“He’s a positive-minded player and person. He just wants to do the best for himself in his career. Everyone is behind him.”
On Friday, England boss Gareth Southgate called Henderson a role model and insisted he could not understand the negative reception.
Elliott will contact his former skipper once England duty is over, with the 20-year-old travelling to Slovakia to face Ukraine with the under-21s on Monday and Henderson preparing for the visit of Italy on Tuesday.
“I didn’t want to make too much of a fuss about it – no-one should. It’s a few individuals who have different points of views, which is fine. I don’t think he would take it to heart too much,” said Elliott, who scored twice in the Young Lions’ 9-1 Euro 2025 qualification rout of Serbia on Thursday.
“He has been through a lot in his career and it’s just another barrier he is going to run through, I’m sure.
“We always keep in touch, when we’re here (St George’s Park) and see those guys we are always having conversations and it’s nice to have that togetherness with the seniors.
“Some of the lads, playing for the big teams here, brings everyone together. It’s nice to be around them and it gives us all a target and goal.”