Jenny Hockey, 70, and Freda Brayshaw, 71, have been charged under Section 241 of the Trade Union and Labour Relations Act 1992, South Yorkshire Police said.
The two women were arrested during a stand off with police and contractors over the felling of trees in Rustlings Road, Sheffield, on 17 November.
They are due to appear at Sheffield Magistrates' Court on 26 January.
Two women arrested during a protest against the felling of eight trees by council contractors have been charged.