Detectives from Scotland Yard arrested the man at a house in Wigan, Greater Manchester, at about 7.45am after appeals on BBC1's Crimewatch UK programme.
He was detained on suspicion of causing a public nuisance and is being interviewed by detectives.
Police launched an investigation in December after a complaint from actress Moira Lister about pornographic letters.
It later emerged that the stalker may have targeted up to 60 women over the last 20 years.
Victims also included former newsreader Jan Leeming, Radio 4 presenter Sue MacGregor and Pan's People dancer Dee Dee Wilde. All the recipients are famous women "of a certain age". Many are stage actresses who were at the height of their popularity in the 1970s and 1980s.
Scotland Yard said that police investigating the stalker had been led to the Wigan area after a call from a Crimewatch UK viewer responding to an appeal on the programme two weeks ago.
Speaking recently about the harassment, McGregor said: "This has gone on long enough. It is more than a nuisance and it is actually against the law."
Related articles
02.08.2000: Convicted stalkers may go on special register
29.01.2000: Stalkers
01.02.1999: Warning of fake stalking claim
Useful links
Anti-stalking website
Gender harassment on the internet
Satlking behaviour
Cyberstalking online guide
