Following the lead of numerous universities, Wellesley College will raise tuition, room and board fees by about 8 per cent next year, John Hartley, vice president of finance and business affairs, said yesterday.

Tuition, now $4300, will increase $350. The present $1000 room and $1250 board charges will both rise $100, bringing total fees from $5550 to $7100.

Hartley blamed the increase on inflation. "We're trying to keep our increases just behind the rise in the cost of living, which last year was 9 per cent," he said.

Increased financial aid will probably counteract part of the cost increase, he said. "About 40 per cent of our students receive some form of aid, and some of these students may need extra help to cope with the extra charges," Hartley said.

Like most other schools, Wellesley relies on student fees and outside grants and donations. But the inflation rate is about one per cent higher than the tuition increase and Wellesley administrators interviewed yesterday differed on whether this gap will increase the college's dependency on outside income.

Hartley and his staff drafted the 1979-80 budget early this month and then proposed a tuition increase to the school's board of trustees. Students received a letter last week announcing the increase.

Lisa A. Blank, a junior, said yesterday that she did not expect students to protest the increase. "You know how it goes. Everyone will just sit back and take it," she said.