A compass was a device that pointed to the north pole of a planet.
The First Doctor once used a power impulse compass taken from the Monk. (TV: The Daleks' Master Plan) He later used an electronic compass while on Tiro. (PROSE: Terror on Tiro)
In the 1900s, while on Fang Rock, the Fourth Doctor attempted to use a compass but found that a strong electrical field caused the needle to spin erratically. (TV: Horror of Fang Rock)
In the 1960s, Sean and Jacko found a compass while working in the mine at Atlantis. They planned to use it in their upcoming escape from the mine, but the mine overseer saw them with it, and ordered a guard to search them. The guard found nothing as Sean had passed it off to Jamie McCrimmon. When Ben Jackson asked why it was so important, Sean replied it was "as important as eyes down here". (TV: The Underwater Menace)
During the Fifth Doctor's quest for the Key to Time, one of its segments was disguised as a compass. (AUDIO: The Judgement of Isskar)
While shopping for presents for her TARDIS companions on 21st century Earth, Tegan found a compass that looked like a fob watch. When she realised some of her money was no longer in circulation, she stole it, rationalising that her future self would pay for it. (PROSE: Last Minute Shopping)
Jem's father had given him a compass with a treasure map hidden inside that lead the Sixth Doctor and Evelyn Smythe to Ruby Island. (AUDIO: Doctor Who and the Pirates)
Dalek seismic detector arms resembled compasses. (TV: The Chase)