Napolitano's office said in a statement that the four were being rewarded "for the highest merits in the scientific, artistic and cultural fields".
Piano is perhaps best know for the Centre Georges Pompidou in Paris, Potsdamer Platz in Berlin and "The Shard", Europe's tallest skyscraper, in London.
Abbado has worked at La Scala opera house in Milan, the London Symphony Orchestra, the Vienna State Opera, and Berlin Philharmonic orchestra.
The two scientists rewarded are Elena Cattaneo, a top biologist working in the field of stem cell research, and Carlo Rubbia, a physicist and winner of a Nobel Prize in 1984 for his work on elementary particles.
Senatorial posts are rarely awarded - the last to receive the title was economist and future prime minister Mario Monti in 2011 - and recipients have full voting powers in the influential chamber.
Under Italy's parliamentary system, the Senate upper house and the Chamber of Deputies lower house, have equal power and the Senate is currently debating an expulsion procedure for Silvio Berlusconi.
The balance between Berlusconi's centre-right forces and the centre-left in the Senate is very close.
The billionaire former prime minister and senator lost a second and final appeal against a conviction for tax fraud earlier this month and he faces possible expulsion from the chamber under a new law.