Josh Taylor's defence of his WBA and IBF world titles against Thailand's Apinun Khongsong has been postponed due to the coronavirus pandemic.
The Scot, 29, was due to make his first defence of his super-lightweight belts at the Hydro in Glasgow on 2 May.
A new date has yet to be announced, while refunds are available for fans.
Dundee fighter Paul Kean's WBO European super-welterweight title fight with Hamzah Sheeraz, scheduled for 11 April in London has also been postponed.
A statement from Queensbury Promotions said: "Following the guidelines and advisory measures announced by both the Government and The British Boxing Board of Control, Queensberry Promotions feel it would be inappropriate to proceed with any forthcoming Boxing promotions in front of live audiences during April and May.
"Refunds are available from the point of purchase. We are currently working with the SSE Hydro, Top Rank and MTK Global to identify a suitable alternative date to reschedule the event for the Scottish fans."
The British Boxing Board of Control made decision to postpone all public boxing events under its jurisdiction, a decision the sport's governing body will review again next month.
The Olympic European boxing qualifying event in London was postponed on Monday, with other bouts either postponed or rescheduled.
Daniel Dubois and Joe Joyce's heavyweight clash on April 11 at the O2 Arena has now been rescheduled to July 11.
Taylor, who became unified IBF and WBA champion with victory over Regis Prograis in October, has to face mandatory challenger Khongsong before hoping to unify the super-lightweight division by facing WBC and WBO champion Jose Ramirez.
Both Taylor and 23-year-old Khongsong, who has only had one fight outside his homeland, have a 16-0 record.