The latest additions were published by the Council of the European Union on Wednesday.
The news came shortly after Mazepin had told the media that neither he nor his father were subject to sanctions, and thus that couldn't be used as an reason for the Haas F1 team to cancel both his contract and that of his sponsor Uralkali.
Mazepin explained in an online conference on Wednesday that his sacking by Haas on March 4 came as a surprise, as he had been given no indication by team principal Gunther Steiner.
He said he had agreed to sign the document prepared by the FIA and which allowed drivers from Russia to compete under a neutral flag.
"I have consented to this ruling unconditionally when it was prepared by the WMSC," he said.
"So the decision from Haas was not based either on any directive from the sport's governing body, or dictated by any sanctions that were placed against either me or my father, or his company."
However, within hours, Mazepin was listed as the 732nd Russian to be sanctioned by the EU, while his father was number 723.
In explaining the decision the EU noted that as the head of Uralkali Mazepin Sr "is involved in economic sectors providing a substantial source of revenue to the Government of the Russian Federation, which is responsible for the annexation of Crimea and the destabilisation of Ukraine".
It also referenced the fact that along with 36 other business people he met with Vladimir Putin on February 24, the day that the Russian invasion of Ukraine began, to discuss its likely impact.
The EU notes that "the fact that he was invited to attend this meeting shows that he is a member of the closest circle of Vladimir Putin and that he is supporting or implementing actions or policies which undermine or threaten the territorial integrity, sovereignty and independence of Ukraine, as well as stability and security in Ukraine.
"It also shows that he is one of the leading businesspersons involved in economic sectors providing a substantial source of revenue to the Government of Russia, which is responsible for annexation of Crimea and destabilisation of Ukraine."
With regard to Nikita Mazepin, the EU flagged his now cancelled F1 involvement and noted that "he is a natural person associated with a leading businessperson (his father) involved in economic sectors providing a substantial source of revenue to the Government of the Russian Federation, which is responsible for the annexation of Crimea and the destabilisation of Ukraine".