Oliver Heldens (born Olivier Heldens; 1 February 1995) is a Dutch electronic music producer and DJ from Rotterdam.

His 2013 song, "Gecko", caught the attention of fellow Dutch DJ Tiësto, who signed him to his label, Musical Freedom, and released the track with vocals from British singer Becky Hill on June 23, 2014. Heldens also has a weekly podcast titled Heldeep Radio, which has been ongoing for over 2 years.

In 2015, he began producing bass house songs under the alias HI-LO, which comes from 'Oli H' in reversed form. Under his alias, Heldens produced three singles titled "Crank It Up", "Renegade Mastah" and "Wappy Flirt",releasing the latter two on his label Heldeep Records.