The direct answer to your question is, "No". There is no "Ubuntu" branded Office Suite.
Ubuntu is an operating system (with a graphical desktop environment), like MacOS, Windows, Android, and many others.
Canonical has been developing the Ubuntu operating system with the help of community volunteers since 2004. Although Canonical does create other software, they do not offer an Office Suite like MS Office in their portfolio of products.
Just as the Windows operating system can run software from different vendors as long as the software is written to run on Windows, Ubuntu can run software from different vendors as long as the software is written to run on Ubuntu (or an equivalent Linux based operating system).
Some of the software Ubuntu runs is Open Source, which means the code is not secretly guarded, unlike most Microsoft or Apple code which is proprietary.
Of course, Ubuntu can also run proprietary software, and the software may be either free or may costs money to purchase.
The other answer here lists some Open Source and Free (no cost) Office Suites.
I'll add a few more that have Propietary licenses; these have versions you can run on Ubuntu, and they have paid or unpaid versions: