Mike Yates is a recurring character in Doctor Who who became an antagonist in the story "Invasion of the Dinosaurs".
He was portrayed by Richard Franklin.
Captain Yates was a member of UNIT who often acted as Brigadier Lethbridge-Stewart's second-in-command. He aided the Doctor and his assistant Jo Grant against a number of threats, including several clashes with the Master and also encountered the Daleks, Nestene and Axons among others.
In "The Green Death", while working undercover at Global Chemical, Mike was brainwashed by the supercomputer BOSS and ended up holding the Doctor and the Brigadier at gunpoint. He was freed by the Doctor using a Metebelis crystal and went on to help them against BOSS but the experience seemed to have an effect on him and he was sent on extended sick leave.
During this time, Yates became involved with Operation Golden Age, a conspiracy led by MP Charles Grover who believed Earth had been ruined by pollution and intended to wind time back across the planet, erasing centuries of history. Only a segment of Central London where they and those who shared their views were sheltering would survive the transition. To this end, the conspirators had a scientist, Professor Whitaker, transport dinosaurs into the area so it would be evacuated.
Yates was among the UNIT taskforce assigned to contain the threat. He reported to Whitaker and to General Finch, who commanded the army troops in the area. When the Doctor arrived on the scene, Yates warned the conspirators that he could uncover their operation. He was convinced to sabotage the Doctor's stun gun with which he intended to capture a dinosaur. However, he was incensed when Whitaker tried to use the opportunity to have the Doctor killed by a tyrannosaur and ended up stunning the beast himself. He then sabotaged the equipment the Doctor had intended to use to monitor the dinosaur's return to the past.
When Grover, Whitaker and Finch framed the Doctor as the one bringing the dinosaurs through time, Yates went along with it, refusing to listen to the Doctor's explanations. He ended up holding the Doctor, the Brigadier and Sergeant Benton at gunpoint when they realised the truth of the conspiracy but was distracted by the entrance of Private Bryson and overpowered by Benton. After the crisis was over, he was offered a chance to resign quietly.
He would end up reconciling with the Doctor during his later appearance in "Planet of the Spiders", where he helped him and his new assistant Sarah against the Metebelis Spiders.