He looks certain to be named in Australia's squad for the World Cup in West Indies and the United States
The 53-year-old West Indies great arrived at Shahjalal International Airport around 9:15pm Saturday.
Bangladesh Cricket Board announced his appointment on Thursday morning on a three-year contract until the 2019 World Cup.
The formalities of the signing are supposed to be completed on Sunday.
The Caribbean fast bowling instructor, who boasts a tally of 519 Test wickets, will meet his new disciples on the same day.
Closing in on his career's first coaching role of a national team, Walsh - the first bowler to reach the landmark haul of 500 Test wickets - was a selector of the West Indies Cricket Board before this assignment.