Now measuring 162.91 metres tall, the Spanish basilica has officially pipped the record from the Ulm Minster in Germany, which has held the crown since 1890.
Designed by acclaimed architect Antoni Gaudí, the place of worship has been under construction in the centre of Barcelona for more than a century, with the main building due to be completed next year.
According to the BBC the central Tower of Jesus Christ will grow with the addition of the rest of the cross over the next few months, eventually standing at 172 metres tall.
The first stone of the Sagrada Família was placed in 1882, with up-and-coming architect Gaudí taking over the project the following year.
He transformed the original designs for the basilica into a far more ambitious proposal, which was initially funded by donations from repentant worshippers.
At the time of his unexpected death in 1926, just one of the planned 18 towers had been built.
In the years following, the construction of the architectural marvel was managed by the Sagrada Família foundation, and funded by contributions from tourists, visitors and private donors.
