Mr McGuinness was returned with an increased majority of 9,953.
Speaking after the count, he said: "This has been a resounding victory for Sinn Fein - we have increased our vote by 5,000 in this constituency," said Mr McGuinness.
"Of course here in Omagh leisure centre the news is quite startling because it looks at this stage that Pat Doherty has also won the West Tyrone seat very decisively.
"And before the end of the day Michelle Gildernew could be joining us as the MP for Fermanagh-South Tyrone.
"This has been an absolutely fantastic performance by Sinn Fein west of the Bann."
Meanwhile, the Sinn Fein President Gerry Adams has held the West Belfast seat with a big increase in his majority.
The SDLP vote collapsed by nearly 10,000 with Mr Adams' vote increased by 10%.
Speaking after the seat was declared, Mr Adams said: "We have the big job of continuing with the peace process, of making sure that the Good Friday Agreement is delivered upon and that people will have a future.
West Belfast result
In 1997, Mr Adams had a majority of 7,909 over the SDLP's Joe Hendron.
He was elected MP for West Belfast in 1983, losing the seat to Joe Hendron in 1992, then regaining it in 1997.
He has never taken his place at Westminster.