Fr Noah Connolly, from Church of the Holy Redeemer in Slough, refused to name the "poor lady".
He told The Times: "She is a Catholic and she is convinced she needs to go to as many masses as possible."
She also attended buffets held by grieving relatives who called the woman's presence intrusive, and criticised her for helping herself.
Margaret Whitehead from Warfield in Berkshire said that the woman attended her daughter Catherine's funeral in August.
She said: "She was eating from the buffet like there was no tomorrow.
"There were a lot of people at the funeral from Catherine's work so I just assumed she was a colleague.
"When I spoke to her though she told me she used to work with Catherine as a waitress. My daughter never worked as a waitress.
"There's mass every morning, she doesn't need to go to funerals. She's only going when there's a cheap lunch."
Fr Connolly said although he is aware of the complaints about the woman attending stranger's funerals, he is powerless to prevent her from attending church services.
He added: "Every funeral we have she comes and if there is a reception afterwards she makes her way to it without invitation.
"I can't exactly say, 'you can't come here'."
