Online banking, also known as internet banking, web banking or home banking, is a system that enables customers of a bank or other financial institution to conduct a range of financial transactions through the financial institution's website or mobile app. Since the early 2000s this has become the most common way that customers access their bank accounts.

The online banking system will typically connect to or be part of the core banking system operated by a bank to provide customers access to banking services in addition to or in place of historic branch banking. Online banking significantly reduces the banks' operating cost by reducing reliance on a branch network and offers convenience to some customers by lessening the need to visit a branch bank as well as being able to perform banking transactions even when branches are closed.

Internet banking provides personal and corporate banking services offering features such as making electronic payments, viewing account balances, obtaining statements, checking recent transactions and transferring money between accounts.

Some banks operate as a "direct bank" that operate entirely via the internet or internet and telephone without having any physical branches relying completely on their online banking facilities.