Gardner's future has been the subject of a lot of debate at the Stadium of Light this season after it became clear he had found it difficult to settle in the North-East.
After becoming a key figure in the Sunderland team under O'Neill, however, the 25-year-old looks happier in a red and white shirt and has outlined a desire to stay at the club.
West Brom made their interest known in him in January but because of a shortage of midfielders there was a reluctance on the manager's part to cash in then.
But the £5m midfielder claims he would have to think twice about leaving in the summer any way, having enjoyed playing for O'Neill since the man who signed him, Steve Bruce, left in November.
Gardner said: "Hopefully I will be here next season. I have a contract, so why not? I really am happy at Sunderland and feel as if I'm playing some good football.
"The fans have been great with me and hopefully they can see I give everything when I go out on to the pitch. I could have scored a couple more goals, but it's my first season up here and your
first season is always difficult."
O'Neill has used Gardner as a midfielder and a full-back during his time in charge, but wherever he has played he has tended to give his all - despite constant suggestions of homesickness.
He said: "I've had a good run of games and we've pushed on since Martin O'Neill came in. The fans have hopefully taken to me and seen why the club bought me. I'd have liked a few more goals but
it's always harder in your first season. I'm happy."
Sunderland have stuttered since the FA Cup quarter-final replay defeat to Everton on March 27, failing to win any of the five matches in the Premier League which have followed.
They now head in to Saturday's visit of Bolton knowing that increasing the Trotters' relegation worries is essential if they are to maintain hopes of a top eight finish.
Sunderland have slipped to 11th and two points adrift of Liverpool in eighth following their recent slump and Gardner is hopeful of a return to winning ways.
He said: "We want to finish as high up the league as we can. To bring in ten players last summer and finish seventh or eighth would be a massive achievement.
"When the manager came in we were in 17th and in a relegation fight, so if you'd have given us where we are now with four games to go, well safe and enjoying it, we'd have said 'thanks very much'.
But we want to keep going and finish on a high."
Once the season has come to a close international football will take over and yesterday saw confirmation of the first call-ups for the summer.
Goalkeeper Simon Mignolet has been named in the Belgium squad for the friendly with England at Wembley on June 2. Stephane Sessegnon, is in line to feature for Benin in World Cup qualifiers against
Mali, Rwanda and Ethiopia.
Nicklas Bendtner, who will be a key member of Denmark's Euro 2012 squad, meanwhile, has reaffirmed he is in no rush to decide his future.
Bendtner, on loan from Arsenal where he has two years remaining on his contract, is likely to be sold.
He said: "Never say never about Sunderland but it is not certain that I will be here if the opportunity arises. About Arsenal, I obviously have to have a chat with the club about it (the future)
but it's not there that the first priority is going to be."