The record for largest block ever mined on a public blockchain has recently been broken by Bitcoin Cash SV (BSV). A mining pool on the BSV network mined a block of 103MB.
At block number 563638, a China-based pool called Mempool mined the record-breaking block. This was the first time that the 100 MB limit has been surpassed for the blockchain, and it allowed 460,400 transactions to be verified in a single block.
The record was broken on January 3 2019, the 10-year anniversary of the mining of Bitcoin's genesis block. The BSV team used this same occasion to launch its new official logo.
Block size has been one of the most contentious issues for the Bitcoin (BTC) network. It is what led to the hardfork and creation of Bitcoin Cash (BCH) back in 2017, and was a major influence on the subsequent hardfork and chainsplit of BCH into BABC and BSV in late 2018.
Interestingly, Craig Wright and the team behind BSV were initially opposed to block sizes larger than 32MB. Many devs and members of the community believe that larger block sizes allow for better scaling of the network but may favour institutional adoption, over individual usage of the crypto for everyday transactions.