According to The Atlantic's Uri Friedman, not necessarily. If you want to be absolutely sure, check with the Chicago Rabinnical Council, who say you can use quinoa. As long as it's from Bolivia, where quinoa production is chametz-free. And even then it's a pain in the tuchus:
...[The Chicago Rabbinical Council] recommends inspecting quinoa before Passover by spreading "one layer of quinoa at a time on a board or plate" and checking to be sure that there are no other grains or foreign matter mixed in with the quinoa"--a time-consuming exercise that Jews rushing to prepare seders are unlikely to embrace. [Friedman 2011]And here I was struggling to find creative ways to avoid meat on Fridays. Silly me.