"The Spanish authorities, NATO and the newspapers did not bring up a single worthwhile argument to back these claims," Kremlin spokesman Dmitry Peskov told journalists.
"We consider these claims to be groundless and more likely a deliberate or inadvertent continuation of the same hysteria that is now happening in the United States and a number of other countries."
Russia faces a barrage of accusations of interfering in a string of seismic political events, including the British vote to leave the European Union and the US election of President Donald Trump.
Spain on Monday raised the issue of "disinformation and manipulation" emanating from Russia during the Catalan independence crisis, at a meeting of European Union foreign and defence ministers.
"I will raise the question of how disinformation and manipulation around the referendum and subsequent events in Catalonia have developed," Spanish Foreign Minister Alfonso Dastis said.
Spain's Defence Minister Dolores de Cospedal said it was clear that a lot of the messaging on social media around the Catalan crisis came from Russian territory, though a definitive link to the government has yet to be proved.
Russian Foreign Minister Sergei Lavrov meanwhile suggested that Madrid was trying to divert attention from Spain's worst political crisis in decades.
"Probably they are arranging this kind of scandalous, sensational hysteria in order to distract the attention of their electorate from their inability to resolve their problems at home," Lavrov said at a news conference in Moscow.