Hove's Patisserie Valerie on Western Road closed permanently this week.
The chain said on social media: "We had to bring the bad news but unfortunately our Hove store has closed Our Patisserie in Eastbourne remains open."
The Brighton branch in East Street closed in January.
In January this year, the firm collapsed into administration but was saved in February after being bought out by Irish private equity firm Causeway Capital Partners.
It is not yet known how many jobs have been lost but staff are believed to have found out about the closure on Monday (July 8), it has been reported.