The 26-year-old, who is 1.83 metres/6ft tall and weighs 120kg/18st 12lb, is currently playing loosehead with French Top 14 side Albi and, although born in New Zealand, he started his career in England with London Irish and Bath.
Albi are looking to establish themselves back in the French top flight this season and Stankovich has been a popular figure in the front row of a side which has made significant strides in the last couple of years.
"Boris has plied his trade in France for five years, which everybody knows is a pretty testing environment," said Tigers forwards coach Richard Cockerill.
"He is a good find for us. It shows our scouting system is working well and we are happy to have him. He has a huge amount of potential, he is the right age for us and it made perfect sense to bring him to Welford Road, especially with the Rugby World Cup coming up early next season when we will lose some of our front-row players."