The call came after the Northern Ireland secretary announced donations made from 1 July would be published.
The commission welcomed the move but said publishing prior donations would ensure "full transparency".
Some political parties have also criticised the move not to backdate the publication of donations.
Parties at Stormont have not been previously been required to reveal who funds them.
"We think it's a positive step that people will be able to see who's donating to political parties, which will therefore increase scrutiny and transparency in our political system," said Ann Watt, head of the Electoral Commission in Northern Ireland.
The body oversees elections and regulates party finances across the UK.
"Legislation was made in 2014 to enable to future publication of any donations from 1 January 2014 onwards, the Secretary of State has chosen to only publish donations from 1 July 2017," Ms Watt told the BBC's Good Morning Ulster programme:.
"That means the public... on the current plans, will not see donations over the last three-and-a-half-years.
"We would welcome full transparency and we would welcome full transparency back from 2014."
She added: "We would be encouraging and lobbying the secretary of state to put in place secondary legislation needed to enable the publication of that data.
"The announcement of future transparency is positive, however seeing the last three-and-a-half-years would be helpful as well, as if you think about it, there have been a lot of elections.
"Political parties may have had a number of quite significant donations and it may be of interest therefore to the public to be able to see those," she said.
The Electoral Commission has called for the publication of donations to political parties in Northern Ireland to be backdated to 1 January 2014.