Norway abolished its licence fee in 2020 and moved funding for its public broadcaster into the national budget. Czech opponents say a similar shift at home would leave public media less free.
The rally was organised by the Million Moments for Democracy association. The group said roughly 400,000 people had attended.
Protesters said the change would stifle media freedom. They oppose replacing the licence fee with money from the national budget.
The government has rejected that warning. It insists the funding shift will not affect editorial independence, but it wants broadcasters to cut costs.
The coalition is led by the populist ANO party and includes two right-wing Eurosceptic parties. Ministers have presented the plan as a spending reform, not a takeover of newsrooms.
Prime Minister Andrej Babis has insisted the government does not want to control public media. He has tied the proposal to pressure on broadcasters to reduce costs.
Thousands of Czechs have taken part in protests over the plan. Sunday's gathering in the centre of the capital was the latest public show of opposition.
The argument is over who pays for public media and how far that money sits from day-to-day politics. Supporters of the licence fee say a direct charge keeps broadcasters further from the budget process. The government says independence can be kept even if funding moves into the state accounts.
The coalition has not accepted that reading. It maintains that editorial independence will survive the change, while still demanding lower costs from the broadcasters.
No date for a final decision was given in accounts of Sunday's protest. The dispute remains between a government set on budget funding and protesters who say the licence fee protects what the public can trust.