The sovereign brought the All England Club to a standstill as she made her first visit to The Championships since 1977, which also brought the last British singles title thanks to Virginia Wade.
She was given a standing ovation from the Centre Court crowd when she appeared in the royal box.
Britain's Andy Murray and Finland's Jarkko Niemenen revived the tradition of bowing to the royal box and received a huge cheer themselves when they stopped just short of their seats, turned and bowed to Her Majesty.
Earlier, in bright sunshine, the Queen walked past Aorangi Terrace -- commonly known as Henman Hill -- before meeting stars of the game on the members' lawn.
The monarch, 84, took lunch with reigning men's champion Roger Federer and five-times champion Venus Williams, as well as British former champions Virginia Wade, Angela Barrett and Ann Jones, plus home favourite Tim Henman.
Strawberries and cream were on the menu, preceded by orange and honey marinated chicken.
Queen Elizabeth walked past Court 18, where John Isner and Nicholas Mahut made tennis history yesterday by playing the longest-ever match. They are due to resume today at 59-59 in the final set.
The sovereign, wearing a powder blue outfit and matching hat, saw an exhibition of junior tennis on Court 14 before strolling through the cheering crowds to meet the players.
The Queen was introduced to defending champions Federer and Serena Williams; past Wimbledon winners Martina Navratilova and Billie Jean King; and some of this year's top seeds, including Rafael Nadal, Novak Djokovic, Andy Roddick, Venus Williams, Caroline Wozniacki and Jelena Jankovic.