The 62-year-old coach has guided Duke to 52 wins in nine seasons.
The Jacksonville, Florida native averaged 14.5 points and a team-high 3.5 assists in 34 games for Duke in 2016-17.
He says he has “a lot of work ahead” of him.
Giles arrived at Duke as one of the nation’s top recruits.
The AP released its Top 100 on Wednesday to combine more than 1,100 polls worth of history dating to January 1949.
The No. 2 seed Blue Devils had averaged 11 turnovers a game this year, but committed 13 in the opening half.
Many fans still traveled from North Carolina since Greenville, South Carolina was still driving distance for them.
Duke’s seeding comes after the Blue Devils won the 2017 ACC Tournament.
This is the Blue Devils’ 20th ACC Tournament title.
Duke will face UNC at 7 p.m. Friday.