Signing an attacker is being treated as a matter of urgency at Selhurst Park ahead of the winter window opening in 13 days.
Spurs are open to bids for Johnson, who scored the winning goal in last season’s Europa League final, with an offer of £35million expected to pave the way for a move.
The 24-year-old has been given a reduced role under Thomas Frank at Spurs this season, starting just six of their 16 Premier League matches, while scoring four times in 875 minutes of football (all competitions).
He signed for Spurs in a £45million-plus deal in September 2023 from Nottingham Forest, where he scored 29 goals and registered 12 assists in 108 senior appearances.
Johnson, capped 42 times for Wales, faces a crucial international break in March, with Wales set to play Bosnia and Herzegovina in their World Cup play-off semi-final.
Victory would see Wales meet either Italy or Northern Ireland five days later for a place at the 2026 World Cup.
As Wales enter a crucial juncture with a World Cup place at stake, a move in search of regular club football could prove beneficial for Johnson.
Palace want a number ten through the door at the beginning of January to offset the impact of losing Ismaila Sarr to the Africa Cup of Nations.
Eagles boss Oliver Glasner has repeatedly called for attacking reinforcements this season, with Johnson capable of playing on both the left and right of attack.
With Daichi Kamada sidelined for 10 weeks due to injury and Sarr currently away with the Senegalese national team, Glasner has been left with just Eddie Nketiah, Yeremy Pino, Romain Esse and Justin Devenny as his senior options to play either side of the striker.
Palace are also in the market for a wing-back, as they look to bolster their right-hand side.
Colombian international Daniel Munoz is sidelined until mid-February after undergoing knee surgery, with Nathaniel Clyne Palace’s sole natural option to play at right wing-back.
The Eagles did not initally plan to sign a right wing-back in January, but have altered their plans in light of Munoz's injury.