Aston Villa beat Derby County 2-1 in the Championship play-off final on Monday and in the process secured the club an estimated £170million windfall.
The Villans experienced heartbreak a year ago when they were beaten by Fulham in the playoff final but goals from Anwar El Ghazi and McGinn were enough to secure promotion at the second attempt.
McGinn joined Villa from Hibernian last summer for only £2.75m and Terry believes the Scotland international has what it takes to make it in the Premier League having been key for the club this season.
As for Jack Grealish, the English midfielder has been heavily linked with a move to Tottenham for over a year but has been a key figure in Dean Smith’s side this season.
The 23-year-old bagged himself six goals and seven assists as Villa finished the season fifth in the table.
But with Villa ending their three-year absence from the Premier League, Terry is confident the club will be able to keep their best players in the summer transfer window.
“Aston Villa going back to the Premier League gives us the chance to keep players like Jack and John as well as other highly valued members of the squad,” the 38-year-old coach said.
“It has been a fantastic season since we came into the club.
“To be where we are now was the target from the outset.
“The gaffer has been great and got us really well organised.
“We’ve got a really good group. There’s a great spirit amongst the lads.
“Nothing compares to playing, but this is still a great feeling.
“Ultimately it is down to the lads out on the field but it is very satisfying knowing that you have been a small part of their success.”
Terry reserved special praise for McGinn and how he contributed in helping Villa return to the top flight of English football.
“Jack gets all the headlines but it’s the work John does,” he said.
“He is superb. You see him day in, day out and he trains how he plays.
“He’s a great professional and he is a great lad.
“John and Jack get on really well both on and off the pitch. You can see it when they’re out on the pitch playing.
“For sure John can take his recent top form into the English Premier League.
“He is well capable of doing that.”