In 2019, he was named the Úrvalsdeild Young Player of the Year and in 2022, he won the Icelandic Cup with Stjarnan.

Hilmar Smári started his senior team career with Haukar, appearing in 7 games during the 2016–17 Úrvalsdeild karla season.

[5] For the season, he averaged 12.4 points, 4.7 rebounds and 3.6 assists per game[6] with the Stjarnan finishing 6th in the league and losing to Valur in the first round of the playoffs.

During Haukar's first round loss against Þór Þorlákshöfn, Hilmar averaged team highs 25.2 points and 6.4 assists along with 4.4 rebounds per game.

[3] Hilmar's father is Henning Henningson,[14] who played 30 games for the Icelandic national team from 1985 to 1993.