The ACT Greens want weekday buses to run every 20 minutes and weekend buses to run every half hour, with the party unveiling its transport policy for the October election.
The party's policy includes a plan to purchase 100 more electric buses and train and hire 200 drivers over the next four years.
They have also pitched extra bus lanes in Belconnen, Molonglo and Civic.
Public transport would be free for pension and concession card holders, regardless of the time of the day. It would also be free for people under-18 and school students would be able to use their student cards to tap on and off.
Bus depots for electric buses would be able in Mitchell and West Belconnen.
The party's transport policy is primarily focused on buses but follows a pitch from the party last month where they said the light rail extension could be built faster than the current timeline.
The plan to increase the frequency of buses would take place from 2026, the party has said.
Under current scheduling, suburban buses run every 30 minutes on weekdays from 6am to 8pm and weekend buses run every hour on a Saturday and every two hours on Sunday.
ACT Greens transport spokeswoman Jo Clay said under the current timetable buses were not frequent enough and the Greens wanted public transport to be an easier option.
"At the moment, too many people are locked into the expense of having a car because there isn't an easy alternative," she said. "Buses aren't frequent enough and the fact remains that they just aren't a genuine option for many Canberrans."
Ms Clay said extra buses, drivers, depots and dedicated bus lanes for the busiest corridors would allow for more frequent services.
The party said it would deliver a bus lane between Belconnen town centre and Civic, ANU to Constitution Avenue and Molonglo to Adelaide Avenue.
The party said beyond 2028 they would focus on increasing the frequency of suburban buses to 15 minutes by 2030.
"The most livable cities all have abundant, frequent and reliable public transport," Ms Clay said.
"The light rail is helping to bring Canberra closer to this, giving thousands more Canberrans a viable alternative to driving. But a strong public transport system needs a quality bus system as well, mirroring and complementing the efficiency of the light rail."
The Greens' transport policy follows one from the Canberra Liberals last month. The opposition will abandon light rail and has promised a continuous bus lane linking the city and Woden.
The Liberals' policy also included a promise to run local buses every 30 minutes during the day, seven days a week, while rapid services would run at least every 15 minutes between 7am and 7pm all week.
The Greens are in government with Labor but the party has criticised their coalition partner over transport.
"Labor holds the transport portfolio but they simply won't deliver," the ACT Greens' public transport document said.
"We have fewer buses today than we had in 1990, Labor won't tell us when they will build the two new depots they committed to and they won't hire enough drivers."
The Greens initially sent out a policy document without costing but an updated document was sent out on Thursday afternoon showing it would cost $100 million for 100 new electric buses.
It would also cost $50 million a year for 200 new drivers.
UPDATE: An earlier version of this article stated the Greens would hire 100 new drivers, the party has said it would be 200 drivers. This was an error in the Greens' initial policy document.
