With the Jags' arrangement with Glasgow-based firm Greaves Sports coming to an end, the Irn-Bru First Division club had to source a new supplier for their strips and associated products that will go on sale to fans.
As part of the deal with the Spanish firm, who also have agreements with SPL side St Johnstone and Thistle's promotion rivals Dunfermline, the club will have a say in the design of future kits, with a retail outlet also set to be opened in the city.
Thistle general manager Ian Maxwell told SportTimes: "We had two or three people interested and we have decided to go with Joma.
"They were keen to point out that they think the fans will appreciate their pricing structure.
"They have got a unit in Port Dundas and they are going to develop some of that into a Partick Thistle shop. At the moment, people would need to go into town to get to Greaves, but now they will be able to go there.
"The club shop will still be open at Firhill on a match day as well. Joma will do our strips and associated merchandising and they are going to try and keep the prices as low as they can, like they have done at other clubs, to hopefully please the fans."
HE ADDED: "I spoke to people at Dunfermline and St Johnstone and they are happy with the quality of the kit. We had some sets down here and the lads were impressed with it.
"Joma will do the tracksuits, the polo shirts, the scarves. It is a similar deal to the Greaves partnership.
"The Greaves deal came to an end and it came to the point where we had to look for a new deal. This is a good one for the club."
The Joma partnership will come into force this summer but it remains to be seen what league Jackie McNamara's side will be playing in when they take to the field in the new kit.
Thistle got their First Division championship challenge back on track at the weekend with a 4-1 home win over Falkirk and Maxwell has urged the Jags faithful to continue playing their part in the title push.
He said: "The crowds have been great at Firhill this season and hopefully we can keep them above that 3,000 mark.
"It was good to see the fans turning out on Saturday on the back of a four-game run where we didn't win. However, our form at Firhill this season has been terrific.
"It is important that we try and keep those numbers up. I would hope that everyone that was here on Saturday would want to come back to the Cowdenbeath game.
"The fans do make a difference so hopefully they keep turning up in their numbers."