Lucille Ball

Real age when show premiered: 40 (b. 1911)
Character's age: 30


https://media.gettyimages.com/photos/lucille-ball-as-lucy-ricardo-in-the-i-love-lucy-episode-building-a-picture-id481101343

Desi Arnaz

Real age: 34 (b. 1917)
Character's age: About 30


https://cdn.quizly.co/wp-content/uploads/2016/02/04190229/Ricky-Ricardo-1.jpg

Vivian Vance

Real Age: 42 (b. 1909)
Character's age: ?, but older than Lucy


https://thiswastv.files.wordpress.com/2013/01/ethel.jpg?w=492

William Frawley

Real age: 64 (b. 1887)
Character's age: ?, but significantly older than everyone else


https://66.media.tumblr.com/30fd8d35f5fcaa7948bbf8c6b21088fd/tumblr_ojqwf2atCb1vf8gq7o1_500.jpg

Lucille Ball

Real age when show premiered: 40 (b. 1911)
Character's age: 30


https://media.gettyimages.com/photos/lucille-ball-as-lucy-ricardo-in-the-i-love-lucy-episode-building-a-picture-id481101343

Desi Arnaz

Real age: 34 (b. 1917)
Character's age: About 30


https://cdn.quizly.co/wp-content/uploads/2016/02/04190229/Ricky-Ricardo-1.jpg

Vivian Vance

Real Age: 42 (b. 1909)
Character's age: ?, but older than Lucy


https://thiswastv.files.wordpress.com/2013/01/ethel.jpg?w=492

William Frawley

Real age: 64 (b. 1887)
Character's age: ?, but significantly older than everyone else


https://66.media.tumblr.com/30fd8d35f5fcaa7948bbf8c6b21088fd/tumblr_ojqwf2atCb1vf8gq7o1_500.jpg

During the first season it was implied that Ricky was 35.

I found out recently the GETTY Images are one of the descendants of old billionaire JP GETTY .