The Dow Jones Industrial Average could hit 15,000 "definitely" by the end of the year, and there's a "very strong possibility" it could go even higher, Wharton School Professor Jeremy Siegel told CNBC on Thursday.
"The earnings haven't been bad," he said. "We're going to see earnings per share five to eight percent higher. We're going to get expanding multiples, which is going to send us well above Dow 15,000."
Siegel said Dow 16,000 or 17,000 is a "very strong possibility," adding, that it could be a "double-digit year."
On Wednesday, the S&P 500 and the Dow industrials took a pause from their recent string of multiyear highs. So far, it's been the best January for the S&P since 1997.
Siegel argued that the recent strength in the stock market has come without major buy-in from individual investors. "The public is just barely touching its toe in the market. We had huge redemptions on stock mutual funds in December. And a little bit of an increase so far in January. So the public isn't really in [yet]."
As for GDP, Siegel predicted three percent growth in 2013 is possible. "You're going to see consumers spending ... to begin to loosen those [purse] strings."
(Read More: Why This Is 'Best-Looking' GDP Drop You'll Ever See)
There also seems to be a more conciliatory tone in Washington these days, Siegel said. Congress has agreed to suspend the debt ceiling until May.
(Read More: Bill to Increase Debt Limit Heads to Senate Vote)
With the borrowing limit issue off the table for now, President Barack Obama and Republican leaders can concentrate on new funding to keep the government running and a replacement for the postponed across-the-board spending cuts known as "the sequester."
"I don't think we're going to have a shutdown of the government. We may have some sequestration."
Any economic headwind from those broad spending cuts would be more than offset by the recovering housing market, Siegel said.
He added that he doesn't think the Federal Reserve is artifically propping up housing prices.
"World interest rates are low. Inflation is low. Real rates are low. I don't think even a point up on mortgage rates is going to kill this [housing] market."
—By CNBC's Matthew J. Belvedere; Follow him on Twitter @Matt_SquawkCNBC