Reuters reported that 83.4 per cent of Booker investors approved the deal; Booker needed the backing of 75 per cent of votes for the merger to go ahead.
Tesco's shareholders overwhelmingly supported the deal in a separate vote, sending shares in both Booker and Tesco upwards.
At time of writing, Tesco's share price had risen 2.5 per cent to 212.4p, while Booker's share price was up 2.3 per cent to 228.7p.
Tesco is hoping that its acquisition of Booker, a wholesaler that also operates a string of convenience chains, will grow its sales in the on-the-go food market.
In the merged company, Charlie Wilson, chief executive of Booker, will become Tesco UK's chief executive.
There were concerns that shareholders might not approve the deal last week, with some major advisory firms coming out against the deal. However, the votes today will give Lewis and Wilson confidence that they have the backing of their investors as they move the group forward.