The 33-year-old centre-back has signed a one-year contract with the Foxes, subject to his registration being cleared by the Football League and the Football Association and international clearance being confirmed.
He will not be available for Tuesday night’s visit of Blackburn Rovers in the Sky Bet Championship, but could feature in Saturday’s trip to Blackpool.
A vastly experienced defender with 60 international caps to his name, Wasilewski joins City as a free agent following a six-year spell with Anderlecht, where he lifted three Belgian league titles and became an immensely popular figure in the Belgian capital.
He has represented Poland at European Championship Finals in 2008 and 2012 and last October, during the current 2014 World Cup qualification campaign, captained his country in their 1-1 draw with England in Warsaw.
On signing, Wasilewski said: "I'm really pleased to be joining Leicester City. I have always dreamed of playing in England so to sign for Leicester is fantastic for me.
"I saw the team beat Wigan at the weekend and was very impressed with everything about the Club. It has been a very good start to the season and I hope to be able to help us win promotion to the Premier League."
Well-known for his powerful approach to defending, Wasilewski also boasted an impressive goal record with Anderlecht – scoring 20 times in 143 appearances.
He began his career with Polish club Hutnik Krakow and gained further experience in his homeland through spells with Śląsk Wrocław, Wisla Plock, Amica Wronki and Lech Poznań before making the switch to Anderlecht in 2007.
Wasilewski went on to represent the ‘Purple & White’ both domestically and in major European competition, featuring in four UEFA Europa League campaigns and the group stages of last season’s UEFA Champions League.
At international level, Wasilewski earned his first call-up to the Poland national side in 2002 and was an ever-present during the group stages of the 2008 and 2012 European Championship Finals – the latter played on home soil. He most recently featured for Poland in their 5-0 World Cup qualifying win over San Marino in Warsaw in March.