Sotiris Billis (Greek: Σωτήρης Μπίλλης; born November 14, 1996) is a Greek professional basketball player and the team captain for Kolossos Rodou of the Greek Basket League. He is a 1.98 m (6 ft. 6in.) tall small forward.

Billis played from a young age with the youth teams of Panionios, before he started his pro career.

Billis signed his first professional contract with the Greek Basket League club Panionios, on 2014. After playing one season with Kolossos Rodou,^[1] he returned to Panionios for a second spell on July 28, 2016.^[2] He rejoined Kolossos the following year, where he stayed for two seasons.

During the 2019–2020 campaign, Billis played with Karditsa of the Greek 2nd division.

In 2020, Billis returned to Kolossos Rodou for the third time. On July 2, 2021, he renewed his contract with the island team for another year. In 16 games, he averaged 2.1 points and 1.2 rebounds in 7 minutes per contest. On August 2, 2022, he re-signed for another season, his sixth overall with the club, and was named vice-captain in the process.^[3] In 9 games, he averaged 1.7 points and 2.1 rebounds in 10 minutes per contest. On August 1, 2023, Billis penned a new contract with Kolossos.