Dr Whittow is believed to have died in a collision on the M40 motorway on 23 December, in which a 29-year-old man from Warwickshire was also killed.
The 60-year-old medieval historian and archaeologist was last month appointed the next Provost of Oriel College – a role he was due to take on from September next year.
Oriel College’s flag was flown at half mast following the news and the college also paid tribute to the man who began his academic teaching there and was due to return next year.
It said: “Mark taught generations of Oriel students and we were looking forward to welcoming him as the College’s next Provost in September 2018.
“A huge loss, and our thoughts are with his family.”
Academics from around the country and across the world, as well as former students, paid tribute to the Corpus Christi College professor of Byzantine Studies.
Corpus Christi president Steve Cowley said “Corpus has taken the news of Mark’s death very hard.
“Mark was a deeply likable man, someone who was generous with his time and concern for other people – one of those rare individuals who plays such a large part in conjuring that mysterious alchemy that helps complicated communities like ours to work.
“Selfishly, we were not looking forward to the time when he was to move to Oriel, but now ours is a much deeper sorrow, rooted in the knowledge that we shall never again have the pleasure of spending time in Mark’s company.
“We send our deepest condolences to his wife Helen and his family, as well as those many people around Oxford and beyond into whose lives Mark brought such enormous pleasure as well as sharing with them his deep understanding of the Byzantine world. We are all going to miss him terribly.”