Across the country, a record 22,506 had to wait more than 12 hours in England's emergency departments last month between a decision to admit and actually being admitted.
In hospitals in Yorkshire and Humber, the situation affected 1,857 patients.
The problem was most acute for the York and Scarborough Teaching Hospitals NHS Foundation Trust where 696 such cases were recorded.
A spokesperson for the Trust apologised for the situation and said: "In recent weeks we have seen a record number of patients in our hospitals who have tested positive for Covid-19. This puts our hospitals under severe strain when coupled with increased staff absence and high numbers of patients waiting to be discharged who no longer need to be in hospital.
"This has an impact on our emergency departments, resulting in patients waiting longer for beds to become available.
"We recognise that this means some patients will spend a long time in the emergency department before they are admitted to a ward, and we are sorry for this.
"We are working with our partner health and care organisations including the ambulance service and social care providers to reduce delays for patients from when they arrive in the emergency department through to when they are ready to go home."
The new figures come just weeks after six A&E departments in Yorkshire urged patients to stay away unless they "really need" to visit.
On Sunday, Chris Hopson, chief executive of NHS Providers, said there were "four big inter-related challenges" facing the NHS - the ongoing impact of Covid, urgent and emergency care pressures, backlogs and staff shortages.
He said on Twitter that in an NHS Providers board meeting last week, health leaders "agreed this was the longest most sustained period of NHS pressure they had seen in their careers".
He said there were "much higher levels of Covid prevalence" than had been predicted, with 15,000 patients with Covid in English hospital beds on April 14 - almost double the 8,000 seen six weeks ago.
Mr Hopson said while the vaccine programme meant serious illnesses and fatalities from Covid were lower, the "operational consequences" were the same for hospitals.
He added there were major pressures on emergency care, including "worryingly high levels of delays in answering 999 calls, conveying patients to hospital, ambulance handover delays outside hospitals, 12 hour waits in A&E and delays for urgent mental health care".
Scarborough's Covid rate falling
Coronavirus infection rates have fallen in Scarborough to their lowest level since February 28 before cases spiked last month, official figures show.
The borough's seven-day rate per 100,000 people is now 320, a drop of 136 in the week to April 16.
It is well below the peak of 1,971 on January 5, but cases have not yet returned to the pre-Christmas low of 260 on December 13.
There were 348 new Covid-19 infections in the seven days to April 16, the latest data available, an average of 49 each day.
It means that Scarborough's rate is above the average in England, which stands at 286 per 100,000, and below the North Yorkshire average which is now 327.
The borough has the fourth-lowest infection rate in the county and Hambleton has the highest at 401.
Richmondshire currently has the lowest rate in North Yorkshire at 264.
Coronavirus cases have fallen across all boroughs in North Yorkshire in the seven days to April 16.
There are 196 patients currently being treated for coronavirus in York and Scarborough NHS Trust hospitals and five in intensive care, as of April 19.
Three people have died in the last seven days to April 19 within 28 days of a positive test in Scarborough, bringing the total to 285.