Staff and players from Ulster Rugby will also host mini rugby coaching sessions at both venues and players aged between six and 12-years-old are invited to come down and join in.
The mini tour follows on from the successful visit to City of Derry RFC last summer and is part of Ulster's long-term community engagement strategy.
The squad last visited Donegal in 2009 when they trained at Letterkenny RFC. Rugby in the county is experiencing huge growth with two new clubs - Finn Valley and Tir Chonaill having been formed in recent years.
Strabane RFC, where Ulster will be based on Thursday, has experienced great success in recent seasons. The club's first team were finalists in the Gordon West Cup in 2012 and 2013.
The north west club has a successful track record of developing talent in the region and will use the visit of Ulster to launch a new mini rugby section.
Commenting on the open training sessions, Ulster's director of rugby David Humphreys said: "The visit of Ulster Rugby to both Donegal Town and Strabane will give fans the chance to see how the senior squad train and give them the opportunity to meet players that they might only have ever seen on television.
"This is a great way to say thank you for the support that the team receives from the north west of the province.
"It is also a way of recognising the important work that both Donegal RFC and Strabane RFC do in promoting rugby. Hopefully these visits will help inspire new players and followers to the game."