Twitter's ad revenue had been declining rapidly since Elon Musk's chaotic £36bn takeover of the company, but the CEO appeared to confirm in a tweet, that some companies had returned.
Amazon is planning to resume multimillion dollar advertising on Twitter, according to reports.
The move will see Amazon ply about $100m (£81.3m) per year into the platform, now owned by Elon Musk, according to Reuters news agency, citing a tweet from the tech blog Platformer.
The tweet by a Platformer reporter said the company's return is pending some "security tweaks" to Twitter's advertising platform.
According to a Bloomberg report, Twitter's CEO Mr Musk has said Apple Inc has also resumed its full advertising.
Neither Amazon or Apple have yet responded to the reports.
Mr Musk laid off half of Twitter's 8,000-strong workforce soon after his takeover, having moved even more quickly to dismiss its top executives.
Elon Musk in Nevada this week
Apple was Twitter's biggest advertiser in the first quarter of this year - spending $48m (£40m) on ads on the social network, but its spending with the platform dwindled.
The world's most valuable firm spent an estimated $131,600 (£110,000) on Twitter ads between 10 and 16 November - down from $220,800 (£184,000) between 16 and 22 October, the week before Musk closed the Twitter deal, according to ad measurement firm Pathmatics.
At the same time, Mr Musk hit out at Apple - claiming it has threatened to block his social network from its app store without explanation.
The billionaire also asked in a series of tweets whether Apple hated free speech and if it would go after Tesla, his electric-car company.
But the CEO appeared to confirm himself in a tweet on Saturday, the news that both Apple and Amazon had returned to Twitter advertising.
Last week, Mr Musk admitted his company had seen a "massive" drop in revenue.
Food firm General Mills and carmaker Audi of America are among a number who have stopped or paused advertising on Twitter since the acquisition.