The Better Together campaign held a campaign rally in Maryhill with voters stating why they want to keep Scotland in the UK.
More than 500 people filled Community Central Halls to hear Mr Darling deliver the 'No Thanks' message.
He was joined by people from around Scotland, including a shipyard worker from Glasgow, a mum from Clydebank, a student from Bishopbriggs and a credit union administrator from Renfrew urging a No vote.
Mr Darling said he did not need to choose between being Scottish and British and said the arguments on the economy and currency, on employment in engineering, financial services and creative industries and on funding public services like the NHS all led to a No vote.
He said: "On every count, we simply and politely say no thanks."
He added: "I want to use these 100 days not to see Scotland divided further but to bring together most of us in this nation around a common vision of Scotland, leading the United Kingdom after September 18, not Scotland leaving the United Kingdom."
He said all pro union parties now agreed there must be more powers for Holyrood and rejected claims they couldn't be trusted.
He said: "Alex Salmond's argument we won't deliver is contradicted by the fact we delivered in 1997 and again in 2012."
The Better Together event with politicians from Labour, Conservative and LibDems in the audience heard from men and women who said they were ordinary voters who had decided to campaign in the referendum.
Claire Lally, who described herself as a mum from Clydebank, hosted the event.
She said: "One of her twins born prematurely, seven years ago required extensive care from the NHS. I decided to get involved with Better Together to ensure our NHS remains the best in the world."
She added: "I'm spending my spare time, which is not a lot, campaigning for my children to keep our country united."
Paul Sweeney, who works for BAE on the Clyde, said his father and grandfather both worked in the shipyards.
He said: "The biggest naval ship in the UK, the aircraft carrier, involved seven shipyards. It's a great statement of what thousands of people across the country working together can achieve."
Shona Munro, an 18-year-old, from Bishop- briggs, about to start university, said she had rejected nationalism.
She said: "The next 100 days are going to decide our country's future and my future within it.
"Nationalism tells me to narrow my horizons and limit my ambitions. It seems unnecessary and old fashioned to me like dial up internet and cassette tapes."
Mr Darling said it was important the debate was not dominated by politicians.He said: "The public can only take so much of politicians."