Turner moved from Barrow in 2014 to join the Crusaders, from whom he got his release to sign a deal with Scott Naylor’s men to the end of the season.
Oldham chairman Chris Hamilton said: “We had to work exceptionally hard to keep Kieran.
“He didn’t want to leave us, but the prospect of playing with London or Batley in the Middle 8s was a huge attraction.
“We kept in touch with Kieran right through the talks and I can’t speak too highly about how he conducted himself.”
Gill, who has scored three tries in four games for Oldham, said he liked the idea of playing in the Middle 8s and going up against Super League sides, but he felt it was more important to remain loyal to Oldham and to his fellow players.
“It was a struggle, but we got it sorted in the end,” Gill said.
“I rang Chris (Hamilton) the other day to tell him how I felt and to let him know that I just wanted to do my bit to make sure we don’t get relegated.
“I’ve bonded well in the past month. Everyone at Oldham seems to have taken to me and I’ve certainly enjoyed being here.”
New-boy Turner had been courted by Oldham on and off for the past year, but had previously remained loyal to Crusaders,
“He was in our sights for a while and we are delighted to get him,” Hamilton said.
Turner is currently recovering from a fractured eye socket, but he expects to be ready to go in round one of the Championship Shield on August 7.
“His loyalty to Crusaders shows the depth of his character,” Oldham coach Naylor said.
“He has all the attributes he needs to be a top-class winger and he makes us a lot stronger in the back three.
“Character plus attributes equals a good signing – and a good signing at such an important part of the season is a good sign of what the club is all about.”
Wigan-born Turner played football until he was 16. He then joined Wigan St Pat’s where he was fast-tracked to the open-age team before being scouted by Warrington Wolves.
A product of the Wolves academy, he had a short spell at Barrow before following coach Anthony Murray to North Wales.
“Oldham have been talking to me off and on since the early part of the year, but they got in touch again a couple of weeks ago and this time I was ready to make the move,” Turner said.
“Chris and Scott ‘sold’ the club to me. I liked what they said about the club and its future.
“I know how much it means to them to stay in this division and hopefully I’ll be able to play my part in achieving it.”