The platform Tiktok – owned by Chinese tech company Bytedance – is suing Montana after the US state hammered a ban on the app earlier in May.
"We believe our complaint will prevail by being based on an extreme amount of precedent and facts," a Tiktok spokesperson told AFP.
Tiktok claims that the new law — which will go into effect next year — violates the constitutionally protected right to free speech.
Through the ban, Montana became the first in the United States to ban Tiktok through legislation.
Chinese rule
The state's Republican governor Greg Gianforte, who signed the law, has justified it with concerns that TikTok will hand over sensitive user information to the Chinese government.
Last week, the state was also sued by five Tiktok users. The plaintiffs argued that the ban on the video app violates their freedom of expression. The lawsuit was filed in federal court just hours after the law was signed.