Parnell joined for the group stage of the T20 Blast, taking six wickets in seven games.
The 25-year-old plays his final game against Somerset on Sunday, before joining South Africa's T20 squad in Bangladesh.
"Hopefully in the future I can come back here either with the South African team or back with Glamorgan," he said.
"It depends on what is available for me. Either another T20 stint or something longer.
"I have really enjoyed my time. It's a really beautiful city [Cardiff] as well and good people who have made me feel at home.
"The club have been good for me and I have thoroughly enjoyed my time in Wales."
Parnell played in Glamorgan's T20 defeat to Surrey on Friday, a third successive loss for the Welsh county which is another significant blow to their hopes of qualifying for the quarter-finals.
It has been a mixed season for Glamorgan, who have won their last four County Championship Division Two fixtures to put themselves in promotion contention.
Despite their recent poor T20 displays, Parnell has been encouraged by what he has seen from Glamorgan in the shortened form of the game.
"They have good potential. I have seen some guys play some good innings and the bowlers have done well also," he added.
"Michael Hogan and Waggy [Graham Wagg] have a lot of experience and someone like Andrew Salter had done well as a youngster and shown what a gutsy cricketer he is. I expect big things from him in the future."
South Africa bowler Wayne Parnell says he would like to return to Glamorgan after his spell with the county ends.