Gareth Southgate's side trailed to Oleksandr Zinchenko's first half strike in the Polish city of Wroclaw.
But Walker ensured England maintained their unbeaten Group C record when he netted just before the interval.
No England player had ever featured in as many as Walker's 77 Three Lions games before finally getting on the scoresheet.
Although England's run of four successive Group C victories came to an end, they remain on course to qualify for next year's European Championship.
England sit six points ahead of second placed Ukraine with three group games left and the top two teams guaranteed to qualify.
"Very tough place to come. You could feel the atmosphere, a unique occasion," Southgate said.
"When you have that much of the ball you want to create more chances but the attacking play didn't click.
"If that is the case you have to make sure you don't lose. To come back and get the point was very important in terms of qualification."
Walker added: "It was a relief. To represent your country this many times, it had been on my mind but now I can finally tick it off."
Ukraine are four points in front of third placed Italy and fourth placed North Macedonia, who meet later on Saturday.
"The players did a very good celebration for the people. There was a very good atmosphere. No-one wants to go home because it is not just about the result," Ukraine coach Sergiy Rebrov said.
It was far from England's best performance, but Southgate saw it as a valuable result on the road to Germany.
Maguire was solid enough despite his lack of game-time, but Ukraine's cautious approach meant he was rarely over-worked.
Jordan Henderson was another controversial selection by Southgate after criticism of the midfielder's move from Liverpool to Saudi side Al-Ettifaq.
There was no sign of protests against Henderson, whose transfer has angered England's LGBTQ+ fans following his previously strong support for the community.
Jude Bellingham's blistering Real Madrid form didn't quite translate into an England shirt on this occasion, while Tottenham's James Maddison struggled to make an impact on his second England start before being replaced after 65 minutes.
- Walker to the rescue -
Ukraine have not been able to play at home since Russia's invasion of the country in February 2022.
However, there are an estimated 200,000 displaced Ukrainians living in Wroclaw and around 40,000 of them packed into the Tarczynski Arena.
After being penned into their own half in the opening stages, Ukraine snatched the lead against the run of play to the delight of their raucous supporters in the 26th minute.
England had gone five and a half hours without conceding a goal, but they were finally breached by a flowing move that climaxed with Yukhym Konoplya's cutback to Arsenal left-back Zinchenko, who swept a clinical finish past Jordan Pickford from 12 yards.
For the first time since the World Cup quarter-final defeat against France last year, Southgate's men were trailing.
But Walker settled their nerves in the 41st minute as the right-back ended his long wait for his maiden England goal.
Dropping deep into midfield, Harry Kane was given too much time and space for a glorious long pass that arrowed towards Walker's run into the area, the defender taking a touch before calmly slotting home from close-range.
Both sides had second half penalty appeals rejected by VAR, with Bukayo Saka closest to winning it when his 25-yard blast cannoned back off the bar.