No, Bitcoin transactions cannot be reversed.

Once a Bitcoin transaction is sent and gets confirmed by the network, it becomes a part of the blockchain, which is an immutable ledger of all transactions. This means that once a transaction is recorded in a block and this block is added to the blockchain, it cannot be changed or reversed.

This immutability is one of the fundamental features of Bitcoin and many other cryptocurrencies. It is vital for the integrity of the network, ensuring that once funds are sent, they cannot be double-spent or taken back without the recipient's cooperation.

However, the irreversible nature of Bitcoin transactions also means that users must be extremely careful when sending funds. If you send bitcoins to the wrong address or send the wrong amount, there is no way to retrieve the funds or correct the transaction unless the recipient is cooperative and agrees to send the funds back to you.