user471: During his lifetime, did the Buddha teach meditation to lay people, or did he teach meditation only to monks? 
Are there any references to this in the Pali Canon or commentaries?
It's clear that all Buddhists, including lay people, should gain the Right View by learning the Dhamma, for that is the first step on the Noble Eightfold Path. There are also references in the Pali Canon for lay people to live a virtuous life, for example in the Sigalovada Sutta.
However, most of the meditation teachings appear to target monks.

user13122: The Buddha taught people according to what interest them. Maybe, there were few lay people interested in meditation while still enjoying lay lifestyle then. 
Though there is no record of such meditation suttas teaching to lay people, I believe a few excellent lay disciples received meditation guidance from the Buddha. For example, there is Uttarā Nandamātā who is described as "the best of women disciples in meditative power (jhāyīnam)". There is also Citta the Householder who is well-versed in meditation. There is a whole fascinating Samyutta about him.

user471: I accidentally came across a sutta with recommendation for householders to allocate periods for meditation. The Buddha gave this advice to Anathapindika the householder, in the presence of 500 lay followers.
From Piti Sutta (AN 5.176):

Then Anathapindika the householder, surrounded by about 500 lay
  followers, went to the Blessed One and, on arrival, having bowed down
  to him, sat to one side. As he was sitting there the Blessed One said
  to him, "Householder, you have provided the community of monks with
  robes, alms food, lodgings, & medicinal requisites for the sick, but
  you shouldn't rest content with the thought, 'We have provided the
  community of monks with robes, alms food, lodgings, & medicinal
  requisites for the sick.' So you should train yourself, 'Let's
  periodically enter & remain in seclusion & rapture.' That's how you
  should train yourself."

Piya Tan wrote in his commentary on Piti Sutta that:

Until recently (even up to the late 20th century), there is a common
  wrong view that spiritual training, especially mental cultivation or
  meditation, is only the domain of the monastic. The laity merely makes
  merit by serving and supporting the monastics. However, it is clear
  from the Pīti Sutta here that spiritual development by way of mental
  cultivation is just as important for the laity.


471: <p>During his lifetime, did the Buddha teach meditation to lay people, or did he teach meditation <strong>only</strong> to monks? </p>

<p>Are there any references to this in the Pali Canon or commentaries?</p>

<p>It's clear that all Buddhists, including lay people, should gain the <a href="https://www.accesstoinsight.org/ptf/dhamma/sacca/sacca4/samma-ditthi/index.html" rel="nofollow noreferrer">Right View</a> by learning the <a href="https://www.accesstoinsight.org/ptf/dhamma/index.html" rel="nofollow noreferrer">Dhamma</a>, for that is the first step on the <a href="https://www.accesstoinsight.org/lib/authors/bodhi/waytoend.html" rel="nofollow noreferrer">Noble Eightfold Path</a>. There are also references in the Pali Canon for lay people to live a <a href="https://www.accesstoinsight.org/ptf/dhamma/sila/index.html" rel="nofollow noreferrer">virtuous</a> life, for example in the <a href="https://www.accesstoinsight.org/tipitaka/dn/dn.31.0.nara.html" rel="nofollow noreferrer">Sigalovada Sutta</a>.</p>

<p>However, most of the meditation teachings appear to target monks.</p>
 13122: <p>The Buddha taught people according to what interest them. Maybe, there were few lay people interested in meditation while still enjoying lay lifestyle then. </p>

<p>Though there is no record of such meditation suttas teaching to lay people, I believe a few excellent lay disciples received meditation guidance from the Buddha. For example, there is Uttarā Nandamātā who is described as "the best of women disciples in meditative power (jhāyīnam)". There is also Citta the Householder who is well-versed in meditation. There is <a href="https://www.accesstoinsight.org/tipitaka/sn/index.html#citta" rel="nofollow noreferrer">a whole fascinating Samyutta</a> about him.</p>
 471: <p>I accidentally came across a sutta with recommendation for householders to allocate periods for meditation. The Buddha gave this advice to <a href="https://www.accesstoinsight.org/lib/authors/hecker/wheel334.html" rel="nofollow noreferrer">Anathapindika</a> the householder, in the presence of 500 lay followers.</p>

<p>From <a href="https://www.accesstoinsight.org/tipitaka/an/an05/an05.176.than.html" rel="nofollow noreferrer">Piti Sutta (AN 5.176)</a>:</p>

<blockquote>
  <p>Then Anathapindika the <strong>householder</strong>, surrounded by about <strong>500 lay
  followers</strong>, went to the Blessed One and, on arrival, having bowed down
  to him, sat to one side. As he was sitting there the Blessed One said
  to him, "<strong>Householder</strong>, you have provided the community of monks with
  robes, alms food, lodgings, &amp; medicinal requisites for the sick, but
  you shouldn't rest content with the thought, 'We have provided the
  community of monks with robes, alms food, lodgings, &amp; medicinal
  requisites for the sick.' <strong>So you should train yourself, 'Let's
  periodically enter &amp; remain in seclusion &amp; rapture.'</strong> That's how you
  should train yourself."</p>
</blockquote>

<p>Piya Tan wrote in <a href="http://www.themindingcentre.org/dharmafarer/wp-content/uploads/2009/12/19.8-Piti-S-a5.176-piya.pdf" rel="nofollow noreferrer">his commentary on Piti Sutta</a> that:</p>

<blockquote>
  <p>Until recently (even up to the late 20th century), there is a common
  wrong view that spiritual training, especially mental cultivation or
  meditation, is only the domain of the monastic. The laity merely makes
  merit by serving and supporting the monastics. However, <strong>it is clear
  from the Pīti Sutta here that spiritual development by way of mental
  cultivation is just as important for the laity.</strong></p>
</blockquote>
