Premier Pauline Marois also says both departures are voluntary, and says there is no crisis in her office.
Shirley Bishop, her director of communications, says she asked to be reassigned to other duties because she needs a break from the hectic pace of the premier's office.
She will return to the legislature in August as a spokeswoman for Culture Minister Maka Kotto.
And speechwriter Stephane Gobeil is moving on after 15 years in politics.
Bishop says her departure has nothing to do with her contradicting Marois in November 2012 when she said the premier was aware of the past legal problems of Daniel Breton, who had been appointed environment minister and was quickly stripped of the role.
Bishop had said Marois had moved beyond the incident and was a good boss. Marois echoed that sentiment in wishing her well.
Gobeil had been known for his pointed remarks on social media, where he also announced his departure.
Both Bishop and Gobeil reiterated their support for the premier.
Bishop dismissed the idea that she was leaving because of political setbacks, with the young Parti Quebecois government suffering low support and high disapproval numbers in recent polls.
She noted that in 2011, when she joined Marois' opposition staff, the party was also languishing at around 18 per cent in the polls.Suggest a correction