Press TV reports.
A Bahraini court on Thursday announced the jail term for Khawaja, accusing her of "using force against a policewoman and insulting her as forces of order tried to disperse an unauthorized rally" on April 21, Lebanon's Daily Star reported.
Khawaja is also accused of obstructing traffic on the same day by blocking a main road in the capital, Manama.
She was arrested one day before the Formula One Grand Prix in Manama while sitting peacefully in the middle of a main road leading to the Bahrain International Circuit.
The female activist was demanding the cancellation of the race and an end to the Saudi-backed crackdown on popular protests.
Zainab has been arrested several times for organizing protests demanding the release of her father, prominent activist Abdulhadi al-Khawaja, who has been on a hunger strike since February.
On Tuesday, a court adjourned to May 27 another case against Zainab al-Khawaja in which she is charged with holding a rally along with another woman in December in the middle of a roundabout on the flashpoint Budaiya Highway, outside Manama.
Another court also fined her 200 dinars (USD 530) on Monday for insulting a police officer.
The Bahraini regime has handed a one-month jail term to rights activist Zainab al-Khawaja for participating in an anti-government protest last month,