Dionne is a Dutch journalist, presenter and former newsreader.

She attended the Elzendaal College and studied communication sciences, her bachelor's degree at Tilburg University and her master's degree at the University of Amsterdam. Stax started in 2007 at NOS Headlines, the predecessor of NOS op 3, as an intern. There she provided weekly overviews of NOS Headlines for the digital theme channel NOS Journaal 24. After completing a second internship at the domestic editorial team, Stax graduated in 2009 from the University of Amsterdam.

In February 2012, Stax became one of the presenters of the news bulletin NOS op 3 on television. In addition to presenting, Stax worked as a domestic editor at NOS Nieuws.[1] In June 2013, she became one of the regular faces of the morning and day broadcasts of the NOS Journaal. She moved on because Annechien Steenhuizen became the presenter of the eight o'clock news. Since May 2015, Dionne Stax also presented the evening bulletins. On December 5, 2015, she presented her first eight o'clock news.

Stax was also on duty at the time of the attacks in Paris at the editorial office of Charlie Hebdo and later during the hostage crisis. She presented additional newscasts. From 2015 Stax presented the election results as the successor of Herman van der Zandt.[2][3] On April 27, 2016, King's Day, in Zwolle, Stax was the first journalist to interview the princesses Amalia, Alexia and Ariane, after asking the princesses' parents questions in the same interview.[4] She last presented the NOS Journaal on 23 August 2019.

In October 2019 she switched from NOS to AVROTROS to present the Radio 1 program Stax&Toine from January 2020 together with Toine van Peperstraten. She stopped doing so in March 2021. In 2019 and 2020 Stax co-presented the Gouden Televizier-Ring Gala. After Caroline Tensen switched to RTL 4, Stax presented the program DNA Unknown from January 2020 to October 2021.