Four people who were jailed for conspiracy to commit subversion in Hong Kong's largest national security trial to date have appealed against their convictions and sentences.

Former activist Owen Chow, former lawmaker Helena Wong, former district councillor Clarisse Yeung and ex-hospital worker Winnie Yu filed their appeals to the High Court on Tuesday.

The hearing date has not been scheduled, according to the judiciary website.

Last week, the High Court handed down jail terms to 45 people for their roles in a scheme aiming to bring down the government by organising an unsanctioned Legco primary poll, with sentences ranging from four years and two months to 10 years behind bars.

The four who lodged the appeals were among those who pleaded not guilty but were convicted after trial.

Chow was slapped with a jail sentence of seven years and nine months; Yu received a prison term of six years and nine months; and Wong and Yeung were each sentenced to six-and-a-half years in jail.