Steketee, 29, will be available for Yorkshire's next game in Division Two, against Gloucestershire at Headingley starting on June 25, and three other fixtures during July - although the club have said there is scope to extend the deal into the back end of the season.
The Queenslander, who was a member of Australia's Test squad in Pakistan last year, has previously played county cricket with Essex. He was the third-highest wicket-taker in the 2022-23 Sheffield Shield, and has 248 at 25.34 in his first-class career.
"Mark is a very talented young player and has performed well in Australia," Darren Gough, Yorkshire's managing director of cricket, said. "With the schedule Yorkshire has - the Blast games followed quickly by Championship cricket - and current injuries in our ranks it was important that we strengthen the side in our bowling resources.
"Mark will be a wonderful addition to our current squad and help give a further boost to our Championship campaign. We have our first Championship win under our belt, and we want to push on from here. Mark can bring something more to our bowling line-up.
"Here at Yorkshire, we are still working hard on getting the balance right between youth and experience and we now feel we have got a squad where we have plenty of opportunities for everyone."
Yorkshire were expected to be challenging for promotion this season, after being relegated on the final day of the Championship in 2022, but were winless in their first five games before holding off Derbyshire's comeback for a three-wicket victory at Chesterfield this week.