no, obito is not tobi (unfortunately)he's madara uchiha. tobi as obito is just some more fan made rubbish(couldn't think of any other word).
according to the anime and manga
To keep in Akatsuki's shadow, Madara eventually took on the disguise of Tobi, giving orders to Pain in secret.
and also madara had both eyes when he fought Konan. He used one on izanagi. That's why he changed it for a rinnegan...
+Obito is one of the Fourth Hokage's student and was Kakashi-sensei's bestfriend. He's also the owner of Kakashi-sensei's sharingan. He died while saving Kakashi-sensei and his other teammate, Rin. On the second hand, Uchiha Madara is one of the akatsuki members and, I guess we could label him as the root of all evil starting from the time when he killed his brother in order to achieve the mangekyuu sharingan to controlling the kyuubi to making Sasuke join the akatsuki and now by bringing forth a war in the shinobi world.

It just doesn't make scense after reading this if tobi was obito.

(sorry for the long answer)

picture below: Madara's broken mask revealing both his Sharingan

it's obito...
he used the name of madara uchiha cause "the name itself brings fear" and to take advantage of it.