The former Scottish first minister will be in the Belgian capital to collect the first Coppieters Award.
A spokesman for Mr Salmond said last week that he would meet Mr Juncker ahead of the awards ceremony.
It comes as the Scottish government prepares to publish its proposals for keeping Scotland in the single market after Brexit.
Mr Salmond's successor as first minister and SNP leader Nicola Sturgeon met Mr Juncker in Brussels in June.
Speaking at the time, Mr Juncker said Scotland had "won the right to be heard in Brussels" and that he would listen carefully to what Ms Sturgeon had to say.
But he stressed that he would not "interfere in an inner British process".
The request for a meeting with Mr Juncker was made by Mr Salmond, who will receive the Coppieters Award in recognition of his "dedication and advocacy for Scotland's right to redefine its political future among a European family of nations".
The Scottish government is exploring potential options for keeping Scotland in the European single market even if the UK as a whole leaves, with its proposals expected to be published next week.
The EU has previously said it will only negotiate a deal with the UK government once Article 50 is triggered and the formal process of leaving the EU begins.
The UK Chancellor, Philip Hammond, said earlier this month that a special Brexit deal for Scotland was "not realistic".
He also said he wanted to work closely with the Scottish government and the other devolved administrations in order to "secure the best possible deal" for all parts of the UK.
Alex Salmond is expected to meet European Commission president Jean-Claude Juncker in Brussels later.