The 30-year-old, who has struggled for years with a series of wrist and knee injuries, is a major crowd-puller but does not have a singles ranking at the moment. The Halle tournament is a traditional warm-up event for Wimbledon.
The Australian's only singles match of the year was a straight-sets first-round loss to American Aleksandar Kovacevic in Brisbane in January.
Kyrgios, who reached the Wimbledon final in 2022, has played just seven singles matches between January 2023 and April 2026.
"Nick Kyrgios has been one of the most dazzling personalities in world tennis for years," Halle tournament organisers said in a statement.
"The Australian is known for his exceptional playing style, characterised by one of the best serves on the tour, spectacular winners, and great creativity.
"At the same time, his emotional personality and charisma attract considerable attention far beyond the sport."
Kyrgios had said earlier this year he would compete in several grasscourt events, skipping the clay season that precedes them. The Halle tournament will be held from June 13th to 21st.
Wimbledon, the third Grand Slam of the year, starts on June 29th.
