The MSP for Caithness, Sutherland and Ross is currently the Minister for Public Health, Women's Health and Sport.
She tweeted the news that she had tested positive for coronavirus on Tuesday night, saying she has no symptoms and is self-isolating with her family.
Ms Todd also praised the work of testing staff and contact tracers.
She said: "I've received a positive Covid test result today.
"No symptoms but am obviously self-isolating with my family now.
"I also want to say thanks to the testing staff and the contact tracers for their work.
"They are on the frontline and are magnificent. Thank you all."
Health Secretary Humza Yousaf also tweeted: "Sorry to hear my friend & colleague @MareeToddMSP has tested positive for Covid.
"Best wishes for a speedy recovery for her and her family."